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Background: Patellar instability, often associated with medial patellofemoral ligament rupture, is prevalent in adolescents. Risk factors include trochlear dysplasia, patella alta, abnormal patellar tilt, and increased tibial tubercle to trochlear groove (TT-TG) distance. Indication: A variety of surgical options are available for addressing patellar instability, and the selection of each technique should be tailored to the unique pathoanatomy of each patient. Medial patellofemoral ligament reconstruction (MPFLR) is indicated for patients with patellar instability, and tibial tubercle osteotomy (TTO) is indicated for patients with a TT-TG >20 mm. Technique Description: An anterior midline incision is performed to expose the patella, patellar tendon, and tibial tubercle. Diagnostic arthroscopy is performed to assess patellar engagement and cartilage integrity, followed by the TTO. Three guidewires are placed with 15° of obliquity, to guide a 6-cm osteotomy, from medial to lateral and from proximal to distal. A distal cortical hinge must be left intact. A 15-mm medial resection of the tibial tubercle is performed to avoid protrusion against the skin, which is followed by medialization of the tubercle and fixation with K-wires until dynamic testing ensures proper alignment and definitive fixation is achieved with cannulated headless screws. A lateral retinacular lengthening is performed to balance patellar forces. MPFLR is executed using a semitendinosus allograft. The graft is anchored to the patella and drawn through a surgically created plane to the medial femoral condyle. The femoral tunnel is created under fluoroscopy guidance, and the graft is then passed and secured. Graft tension and patellar mobility are adjusted according to dynamic testing. Once patellar stability is achieved and maintained through range of motion, the graft is then fixed. Results: Patients can expect improved clinical outcomes with a high return-to-sports rate following both isolated MPFLR and concomitant TTO. The combination of MPFLR + TTO significantly reduces revision rate, compared to isolated MPFLR in patients with increased TT-TG distance, and enhances postoperative patellofemoral tracking. Discussion/Conclusions: MPFLR + TTO improves patellofemoral tracking and corrects patellar instability, substantially improving postoperative outcomes compared to MPFLR alone. Patients with patellar instability and an increased TT-TG may be effectively treated with MPFLR + TTO. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

ABSTRACT: Introduction: This study evaluates the inter-rater reliability and accuracy of radiographs in assessing healing of osteochondral allografts (OCA) in the knee compared with computed tomography (CT) imaging is currently unknown. Methods: A retrospective review patients who underwent OCA transplantation with postoperative knee radiographs obtained at three and six months, and CT scans obtained at six months was conducted. Three board-eligible orthopaedic surgeons independently graded postoperative radiographs, utilizing the grading scale established by Oladeji et al (2017), and the CT scans utilizing the grading scale established by Gelber et al (2021). Their consensus measurements served as a comparative gold standard. Results: Among 44 prospectively imaged grafts, 13 (29.5%) had radiographs at three months and 28 (63.6%) had radiographs available for evaluation at six months. Assessment of radiographic integration demonstrated low reliability (Intraclass correlation coefficient (ICC): -0.02 to 0.14). On CT scan, this improved to fair reliability (κ = 0.29, P

Introduction: Clinical decision-making is highly based on expert opinion. Machine learning is increasingly used to develop patient-specific risk prediction analysis to improve patient selection prior to surgery. Objectives: To develop machine learning algorithms to predict failure of surgical procedures that address cartilage defects of the knee and detect variables associated with failure. Methods: An institutional database was queried for cartilage procedures performed between 2000 and 2018. Failure was defined as revision cartilage surgery or knee arthroplasty. One hundred and one preoperative and intraoperative features were evaluated as potential predictors. Four machine learning algorithms were trained and internally validated. Results: One thousand and ninety-one patients with a minimum follow-up of 2 years were included and underwent chondroplasty (n = 560; 51%), osteochondral allograft transplantation (n = 306; 28%), microfracture (n = 150; 14%), autologous chondrocyte implantation (n = 39; 4%), or osteochondral autograft transplantation (n = 36; 3%). The Random Forest algorithm was the best-performing algorithm, with an area under the curve of 0.765 and a Brier score of 0.135. The most important features for predicting failure were symptom duration, age, body mass index, lesion grade, and total lesion area. Local Interpretable Model-agnostic Explanations analysis provided patient-specific comparisons for the risk of failure of an individual patient being assigned various types of cartilage procedures. Conclusions: Machine learning algorithms were accurate in predicting the risk of failure following cartilage procedures of the knee, with the most important features in descending order being symptom duration, age, body mass index, lesion grade, and total lesion area. Machine learning algorithms may be used to compare the risk of failure of specific patient-procedure combinations in the treatment of cartilage defects of the knee.

Purpose: To investigate the feasibility and accuracy of 3-dimensional (3D) iPhone scans using commercially available applications compared with computed tomography (CT) for mapping chondral surface topography of the knee. Methods: Ten cadaveric dysplastic trochleae, 16 patellae, and 24 distal femoral condyles (DFCs) underwent CT scans and 3D scans using 3 separate optical scanning applications on an iPhone X. The 3D surface models were compared by measuring surface-to-surface least distance distribution of overlapped models using a validated 3D-3D registration volume merge method. The absolute least mean square distances for the iPhone-generated models from each scanning application were calculated in comparison to CT models using a point-to-surface distance algorithm allowing regional “inside/outside” measurement of the absolute distance between models. Results: Only 1 of the 3 scanning applications created models usable for quantitative analysis. Overall, there was a median absolute least mean square distance between the usable model and CT-generated models of 0.18 mm. The trochlea group had a significantly lower median absolute least mean square distance compared with the DFC group (0.14 mm [interquartile range, 0.13-0.17] vs 0.19 mm [0.17-0.25], P = .002). iPhone models were smaller compared with CT models (negative signed distances) for all trochleae, 83% of DFCs, and 69% of patellae. Conclusions: In this study, we found minimal differences between a 3D iPhone scanning application and conventional CT scanning when analyzing surface topography. Clinical Relevance: Emerging 3D iPhone scanning technology can create accurate, inexpensive, real-time 3D models of the intended target. Surface topography evaluation may be useful in graft selection during surgical procedures such as osteochondral allograft transplantation.

Background: Chondral injuries in the knee are commonly discovered during knee arthroscopy procedures. Due to the poor restoration potential and avascular nature of cartilage, large defects are commonly treated with such surgical procedures. Treatment utilizing an osteochondral allograft (OCA) transplant for symptomatic focal cartilage defects in the patellofemoral joint has demonstrated strong, lasting clinical and radiographic outcomes. Indications: Active and otherwise healthy patients are indicated for surgery when presenting with significant joint-line pain and a large focal chondral defect verified on advanced imaging after an extensive course of nonoperative management. Technique Description: Beginning with diagnostic arthroscopy to confirm the large defect of the medial femoral condyle, we proceeded with OCA transplantation. A small medial peripatellar arthrotomy is performed. The fat pad is removed for visualization and retractors are placed both medially and laterally to appropriately visualize the defect. The defect is then sized according to the appropriate sizing guide. The guide is then placed perpendicular to the defect, and a central guide pin is drilled. A scoring reamer is used to carefully cut the size of the defect followed by a central reamer to prepare the defect. Any debris is removed, and the incision is thoroughly irrigated. The defect is then carefully measured in all four quadrants to match the donor. Any underlying bone is impacted for a stable base. A drill is then used for appropriate marrow venting underneath the defect. The corresponding donor site is selected and reamed with continuous irrigation to prevent thermal necrosis. The plug is removed and carefully measured to match the recipient site. The plug is thoroughly irrigated with pulse lavage to remove marrow elements. The graft is carefully inserted with gentle manual pressure until it is seated perfectly flush with the surrounding cartilage. Results: Clinical research has demonstrated good-to-excellent long-term survivorship of OCA transplantation. Long-term return to sport rates for recreational and competitive athletes are upward of 75%. Discussion/Conclusion: As surgical techniques continue to develop, surgeons should consider utilizing OCA transplants to treat large chondral defects in the patellofemoral joint. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

A lateral opening-wedge distal femoral osteotomy is useful to offload the lateral tibiofemoral compartment for focal chondral defects or isolated lateral compartment arthritis. Although beneficial for these lateral compartment disorders, a distal femoral osteotomy requires careful forethought to optimize correction accuracy and safety. We recommend the following for effective execution of a distal femoral osteotomy: (1) Plan the desired correction preoperatively while accounting for an individual patient’s anatomy and femoral width. (2) Perform an iliotibial band Z-lengthening for large deformity corrections to not overconstrain the lateral structures. (3) Use the plate to help guide the level of the osteotomy, which will facilitate bony contact after the osteotomy and decrease plate prominence. (4) Perform the osteotomy with a saw anteriorly and an osteotome posteriorly for safety and stop the osteotomy approximately 1 cm short of the far cortex. (5) Fashion tricortical wedge grafts at the height of the planned correction to maintain reduction and facilitate plate placement. (6) Control the plate position to lie optimally at the level of the osteotomy, ensuring it is not proud and is parallel with the femoral shaft. With these presurgical and intraoperative steps, a lateral opening-wedge distal femoral osteotomy can be performed effectively.

We present an evidence-based approach to optimize the biologic incorporation of osteochondral allografts: (1) The donor graft is gradually rewarmed to room temperature to reverse the metabolic suppression from cold storage. (2) The graft is harvested while submerged in saline to limit thermal necrosis. (3) Subchondral bone depth is preferred at 4 to 6 mm depth (total plug depth ∼5-8 mm including articular cartilage) to reduce graft immunogenicity and to promote incorporation. (4) The bone is prepared with grooves/beveling to decrease impaction forces, increase access to subchondral deep zones during preparation, and promote graft-host interface healing. (5) High-pressure pulsed lavage is used to reduce antigenicity by removing marrow elements. (6) Pressurized carbon dioxide following pulsed lavage further reduces marrow elements and improves graft porosity for orthobiologic incorporation. (7) Orthobiologic substances (e.g., concentrated bone marrow aspirate) may enhance incorporation on imaging and result in greater osteogenic potential. (8) A suture is placed behind the graft to facilitate removal and repositioning; atraumatic graft insertion without high impaction forces maintains chondrocyte viability. These evidence-based pearls for osteochondral allograft handling optimize metabolic activity, reduce thermal necrosis, reduce antigenicity with removal of marrow elements, enhance biologic potential, and maintain chondrocyte viability to optimize biologic healing and clinical success.

Background YouTube has become a popular source of healthcare information in orthopedic surgery. Although quality-based studies of YouTube content have been performed for information concerning many orthopedic pathologies, the quality and accuracy of information on the rotator cuff have yet to be evaluated. The purpose of the current study was to evaluate the reliability and educational content of YouTube videos concerning the rotator cuff. Methods YouTube was queried for the term “rotator cuff.” The first 50 videos from this search were evaluated. Video reliability was assessed using the Journal of the American Medical Association (JAMA) benchmark criteria (range, 0–5). Educational content was assessed using the global quality score (GQS; range, 0–4) and the rotator cuff-specific score (RCSS; range, 0–22). Results The mean number of views was 317,500.7±538,585.3. The mean JAMA, GQS, and RCSS scores were 2.7±2.0, 3.7±1.0, and 5.6±3.6, respectively. Non-surgical intervention content was independently associated with a lower GQS (β=–2.19, p=0.019). Disease-specific video content (β=4.01, p=0.045) was the only independent predictor of RCSS. Conclusions The overall quality and educational content of YouTube videos concerned with the rotator cuff were low. Physicians should caution patients in using such videos as resources for decision-making and should counsel them appropriately.

Background: Focal articular chondral lesions are a common finding among patients presenting with knee pain. If symptomatic and unresponsive to conservative treatment, cell transplantation techniques offer a unique solution to address larger defects by engineering chondrocytes to integrate within the subchondral bone of the lesion and regenerate cartilage. Objectives: The purpose of this article is to review the evaluation of, and clinical decision making for, patients being considered for cell transplantation and the available techniques an orthopaedic surgeon has at their disposal. Methods: A review of recent literature regarding cartilage defects in the knee and cell transplantation techniques was performed to provide strategies for evaluating and treating chondral defects with matrix-induced autologous chondrocyte implantation (MACI) or particulated juvenile allograft cartilage (PJAC) procedures. Results: Chondral defects in the knee can be treated with patients’ own chondrocytes embedded into a collagen membrane as a MACI procedure, or minced autologous donor cartilage that is then implanted onto a scaffold as a PJAC procedure. These cell transplantation techniques offer advantages compared to bone marrow stimulation or mosaicplasty, and have shown clinically significant improvements in outcome scores with low rates of complications. Conclusion: Cell transplantation techniques such as MACI and PJAC offer treatment options that can effectively address large full-thickness chondral defects in the tibiofemoral joint or patellofemoral joint that may respond poorly to bone marrow stimulation or mosaicplasty.

Background: Nearly half a million rotator cuff repairs are performed annually in the United States. Rotator cuff healing occurs at the interface between the tendon and greater tuberosity, known as the enthesis. Given that a significant number of rotator cuff tears do not heal following surgical repair, multiple adjunctive strategies have been devised to improve the structural integrity of the repaired construct. Recently, a biphasic, demineralized allograft bone implant has been developed to improve enthesis healing. Indications: Relative indications for use of tissue augmentation include greater tuberosity osteopenia, revision rotator cuff surgery, attenuated rotator cuff tissue quality, and massive rotator cuff tears. Relative contraindications include a history of infection and recent immunosuppression. Technique Description: Following preparation of the footprint with an arthroscopic burr, two triple-loaded PEEK suture anchors were placed along the medial aspect of the greater tuberosity. Sutures were then passed through the rotator cuff tendon in a horizontal mattress configuration, and each pair of suture limbs were tied along the medial row. To aid in arthroscopic passage, the biphasic graft is folded longitudinally and clamped with a curved hemostat. The graft is loaded into an arthroscopic cannula and both are delivered simultaneously through a lateral arthroscopic portal. Two 18-gauge spinal needles are placed percutaneously to fix the allograft in the desired position. Subsequently, double-row transosseous-equivalent rotator cuff repair with standard techniques is done, which provides sufficient stability to the graft. Discussion: In a series of 192 patients who underwent arthroscopic rotator cuff repair augmented with a similar bioinductive collagen implant, patients demonstrated significant improvement in patient-reported outcomes at 1 year postoperatively. Moreover, a meta analysis published in 2022 demonstrated a significantly reduced retear rate among patch-augmented rotator cuff repairs as compared to isolated rotator cuff repairs. Conclusion: Tissue augmentation can be performed efficiently and reproducibly to promote biologic healing of arthroscopic rotator cuff repairs. The specific biphasic cancellous allograft presented in this video may be a viable treatment adjunct in the setting of deficient greater tuberosity bone stock, revision cases, or impaired native enthesis healing; however, further research is needed to assess clinical outcomes associated with its use. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Background: Patellofemoral anatomy allows for substantial freedom of motion. Medial patellofemoral ligament (MPFL) tears occur in up to 96% of lateral patellar dislocations. Risk factors for subsequent instability include maltracking and increased tibial tubercle to trochlear groove (TT-TG) distance. Indication: Medial patellofemoral ligament reconstruction (MPFLR) with concurrent tibial tubercle osteotomy (TTO) is indicated in patients with recurrent dislocation or unresolved apprehension. Concurrent TTO should be considered for TT-TGs 15-20 mm depending on overall clinical picture and risk factors. We strongly consider TTO for TT-TGs ≥20 mm and for revision procedures. Technique Description: Following diagnostic arthroscopy, a midline incision is made from the inferior patellar pole to 3 cm beyond the tibial tubercle. The anterior compartment is incised and retracted laterally. An osteotomy guide is affixed to the tibia and an osteotomy cut is made with a saw, leaving a small bridge of periosteum distally. The osteotomy is competed proximally with osteotomes, then medialized and held in place with two 4.5-mm screws. An incision is made on the superomedial patella and two 0.045 inch guidewires are placed at the MPFL insertion and overdrilled with a 3.5-mm drill. A 22-cm semitendinosus allograft is prepared and fixed to the patella using two 3.5-mm anchors. An incision is made over the medial epicondyle and a 2.4-mm beath pin is placed at Schöttle point. Isometry is confirmed and the pin is overdrilled with a 6-mm reamer. The allograft is passed just superficial to capsule from the peripatellar incision to the medial incision, docked into the femur, and secured with a 6-mm interference screw at 30° of flexion after confirmation of appropriate graft length. Results: Studies have demonstrated improved outcomes for patients undergoing MPFLR + TTO compared with isolated MPFL in the setting of maltracking and increased TT-TG distance. In addition, a recent meta-analysis demonstrated no negative effect of concurrent TTO on return to sport timeline. Discussion/Conclusion: MPFLR with concurrent TTO is effective, with surgical correction of underlying maltracking and satisfactory return to sport. Consideration to MPFL + TTO should be given to patients with recurrent instability and pathologically increased TT-TG. The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Background: As the number of total shoulder arthroplasties (TSAs) performed annually increases, some surgeons have begun to shift toward performing TSAs in the outpatient setting. However, it is imperative to establish the safety of outpatient TSA. The purpose of this systematic review was to define complication, readmission, and reoperation rates and patient-reported outcomes after outpatient TSA. Methods: A systematic review of the literature was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using three databases (PubMed, Ovid, and Embase). English-language publications describing results on complication rates in patients who underwent TSA in an outpatient or ambulatory setting were included. All nonclinical and deidentified database studies were excluded. Bias assessment was conducted with the methodologic index for nonrandomized studies criteria. Results: Seven studies describing outcomes in outpatient TSA were identified for inclusion. The included studies used varying criteria for selecting patients for an outpatient procedure. The total outpatient 90-day complication rate (commonly including hematomas, wound issues, and nerve palsies) ranged from 7.1%-11.5%. Readmission rates ranged from 0%-3.7%, and emergency and urgent care visits ranged from 2.4%-16.1%. Patient-reported outcomes improved significantly after outpatient TSA in all studies. Two studies found a higher complication rate in the comparative inpatient cohort (P = .023-.027). Methodologic index for nonrandomized studies scores ranged from 9 to 11 (of 16) for noncomparative studies (n = 3), while all comparative studies received a score of a 16 (of 24). Conclusion: Outpatient TSA in properly selected patients results in a similar complication rate to inpatient TSA. Further studies are needed to aid in determining proper risk stratification to direct patients to inpatient or outpatient shoulder arthroplasty.

The lateral patellofemoral ligament acts to resist medial displacement of the patella. When medial subluxation occurs, it usually has an iatrogenic cause such as prior lateral release, an over-tightened medial patellofemoral ligament reconstruction, or detachment of the vastus lateralis from the patella. The justification for lateral retinacular release has historically been to address extensor mechanism issues such as imbalance of the mechanism due to increased retinacular tension. We present a Technical Note on the treatment of chronic medial patellar instability due to a previous lateral retinacular release using a soft-tissue reconstruction approach with a semitendinosus allograft.

Background: Lateral patellar instability is common in young, active patients. Patients who fail conservative treatment may benefit from medial patellofemoral ligament (MPFL) reconstruction. Indications: Recurrent lateral patellar instability. Technique Description: Examination assesses patellar translation, eversion and range of instability. Diagnostic arthroscopy is performed for loose bodies, cartilage damage, trochlear dysplasia, and tracking. A longitudinal incision is made from superomedial to mid-body of the patella. The plane between the capsule and retinaculum is developed for palpation of the medial epicondyle and adductor tubercle. Electrocautery and rongeur are used to create a trough on the patella from centromedially to superomedially. Two suture anchors are placed at the proximal and distal trough. Fluoroscopy is utilized to identify Schöttle point with a perfect lateral radiograph. A 3-centimeter incision is made, and blunt dissection connects the 2 incisions in the developed plane. A guidepin is advanced at Schöttle point, and suture anchor sutures are shuttled through the plane, posterior to the guidepin. There should be loosening of tension with knee flexion. A semitendinosus allograft is whipstitched with terminal tapering. The whipstitched end is tunneled around the guidepin and brought back to the patella, so that both ends have an excess of 20 to 25 millimeters, and excess graft is trimmed from the free end prior to whipstitching. The doubled graft is sized. The midportion of the tendon is tagged and passed through both anchors. The graft is tensioned to the patellar trough and the graft ends are advanced through the developed plane. The femoral tunnel is reamed, and the graft is tensioned into the tunnel after nitinol wire placement with the knee in full extension. Isometry and lateral patellar translation are assessed, aiming for 1 quadrant with firm endpoint. The patella is proximalized and the tensioned graft is secured with an interference screw. Results: MPFL reconstruction is successful for the majority of patients, with 1.2% reporting instability, 3.6% apprehension, and 3.1% reoperation. Possible complications include patellar fracture, patellofemoral pain, and knee stiffness (loss of range of motion). Discussion/Conclusion: Lateral patellar instability is common, and MPFL reconstruction is typically successful for the majority of patients.

Background: As the popularity of Osteochondral allograft (OCA) transplantation increases, studies have commonly investigated potential risk factors that may influence OCA transplantation survivorship. Objectives: To investigate which risk factors of OCA transplantation failure have been evaluated, which have been found to be significant, and the frequency of inclusion of identified risk factors. Data sources: EMBASE, OVID, and Medline Study eligibility criteria: Studies investigating failure after OCA transplantation comparing or investigating one or more risk factors for failure through any statistical approach. Study appraisal and synthesis: All investigated failure risk factors and associated statistical significance were extracted and tabulated by study. The frequency of significance of each factor and inclusiveness of risk factor analysis by each study were assessed. Results: A total of 15 studies were included for qualitative analysis. Age, sex, body mass index (BMI), previous surgeries, and lesion location were among the most frequently investigated variables. Only BMI and previous surgeries were significant in more than one study. Limitations: There was heterogeneity in surgical techniques and varying definitions of failure utilized by each study, making a direct comparison difficult. Conclusions and implications of key findings: OCA failure risk factor analyses are limited primarily to basic demographic factors (eg, age, sex). Furthermore, only 2 identified risk factors were significant in more than one study, limiting the ability to make evidence-based decisions with the current data available. This information could impact operative planning, the decision to perform an OCA over other cartilage restoration procedures, and patient expectations. Systematic review registration number: CRD42021282852

Background: Patellar instability is a common clinical condition in skeletally immature individuals. Surgical treatment is considered when risk of recurrence is high. Indications: Distal femoral osteotomy is indicated in the setting of obligate flexion dislocation where femoral valgus contributes to a shortened lateral column, with concurrent quadriceps procedures considered for chronic contracture and medial patellofemoral ligament (MPFL) reconstruction for added stabilization. Technique Description: This procedure is performed in a stepwise manner as some components may not be necessary based on the patient’s specific anatomy. The procedure begins with a lateral iliotibial (IT) band soft tissue release or lengthening if possible. The distal femoral osteotomy is then performed utilizing a lateral opening wedge technique. Bone graft is placed in a structural fashion to maintain the correction while a locking plate is inserted. In patients with chronic lateral patellar dislocation, correction of bony alignment may not completely restore tracking. If lateral maltracking persists after further distal soft tissue release, a VY-lengthening quadricepsplasty can be considered. To perform this, the vastus lateralis (VL) is first released. In this patient, the patella was able to be stabilized centrally after VL release, and therefore, the VY-plasty was not performed. The soft tissue attachments for the final MPFL reconstruction are then prepared, including two at the superomedial and midbody of the patella and one at the adductor tendon. The whip-stitched graft is then passed through the adductor sling followed by the patellar periosteal tunnels with the knee in slight flexion to ensure centralization within the trochlear groove. Examination under anesthesia before final fixation of the reconstruction should demonstrate 1A lateral translation. Results: Correction of distal femoral valgus with osteotomy, in isolation or in combination with other patellar stabilizing procedures, has demonstrated significant improvement in patient-reported outcomes and reduced redislocation rates. However, large cohort studies are limited. Discussion/Conclusion: Both osseous and soft tissue abnormalities are important to consider in since they can contribute in varying degrees to patellar maltracking. Therefore, assessment of patellar tracking should be performed frequently to guide extent of surgical correction necessary.

Background: Trochlear dysplasia represents one of the main anatomic risk factors for patellar instability, with risk of failure and unfavorable clinical outcomes in patients with unaddressed dysplasia undergoing patellar stabilization. Indications: Patients with trochlear dysplasia characterized by supratrochlear prominence (DeJour B or D) and recurrent patellar instability, especially following failed soft tissue or bony stabilization. This technique addresses an anterior trochlea without pathologic convexity, as convexity may require conversion to other techniques for groove deepening (eg, DeJour “thick flap” or Schottle “thin flap”). Technique Description: A 6-cm lateral parapatellar arthrotomy is created. A marking pen is used to identify the native center of the trochlea, as well as the location of the planned resection and bony hinge point laterally. An osteotome is used to remove a wedge of bone proximally, such that the posterior aspect of the osteotomy is in line with the anterior femoral cortex. A resection guide is then used to perforate the lateral cortex, with care to avoid damaging the cartilage, and carried laterally and distally to ensure the bony cuts are connected, creating the bony flap. To ensure that all bony bridges are eliminated, the arthroscope is placed into the osteotomy to visualize reduction of the trochlea with manual pressure. A knotless PEEK anchor loaded with 8 loaded sutures is then placed on the roof of the trochlear notch. Sutures are then secured using anchors placed at the center of the trochlea, at the superolateral corner and far lateral edge of the trochlea to reduce the osteotomy, with 2 to 3 sutures placed in each anchor depending on surgeon preference. Results: Trochleoplasty has been reported to decrease the rate of recurrent patellar dislocation while improving mean Kujala score and knee function. Benefits of trochleoplasty must be balanced against the high rate of potential complications, primarily pain and decreased knee range of motion, secondary to the technical challenges and steep learning curve inherent to effectively performing the procedure. Discussion/Conclusion: Patients with recurrent patellar instability with trochlear dysplasia and failed prior stabilization may experience improved stability and outcomes following trochleoplasty.

Background: Medial patellar instability is rare but may occur after lateral retinacular release. The lateral patellofemoral ligament is a significant stabilizer for medial and lateral patellar displacement, and soft tissue–based reconstruction may restore its stabilizing effect. Indications: Lateral patellofemoral ligament reconstruction (LPFLR) is indicated for patellar instability failing exhaustive nonoperative measures. Technique Description: Diagnostic arthroscopy for medial patellofemoral ligament (MPFL) status, patellar tracking, chondral status, and postoperative changes of lateral retinacular release is conducted. A 5-cm incision is made between the midpoint of the patella and the lateral epicondyle, or a single midline incision can be used if performing a concomitant MPFL reconstruction. Dissection is carried down to the lateral retinaculum and capsule, and two 1-cm incisions are made at the distal and proximal patella through the patellar and quadriceps tendon, respectively. The lateral epicondyle is then directly palpated, and two 1-cm incisions are made directly anterior and posterior to the epicondyle into the iliotibial band in full extension. A hamstring allograft is then shuttled in a V-shaped configuration from the quadriceps tendon through the iliotibial band and finally to the patellar tendon. Excess graft is trimmed and doubled over proximally and distally to replicate the normal (or contralateral) 0° to 15° of patellar eversion. Trial resting length and tension is set with temporary sutures through the proximal and distal doubled graft in full extension. The knee is taken through full range of motion to ensure there is no graft tightening in flexion or loosening in full extension. Eversion and patellar translation are then examined. Heavy nonabsorbable sutures are used to set length of the doubled allograft proximally and distally. Results: Case series of LPFLR have demonstrated significant improvements in patients’ pain, Lysholm score and Knee Injury and Osteoarthritis Outcome Score, and kinesiophobia with no instability events and normal range of motion at short-term follow-up. Discussion/Conclusion: Medial patellar instability can occur following lateral retinacular release and patients experiencing instability despite nonoperative treatment are likely to benefit from a soft tissue–based LPFLR. Although other nongraft-based techniques may confer similar outcomes, the authors find it more reliable to perform a lateral reconstruction as described.

Background: Meniscal root tears are radial tears occurring at or within 1 cm of the meniscal root attachment. These injuries have been shown to be the biomechanical equivalent of a total meniscectomy and are thought to be responsible for a rapid progression of osteoarthritis if left untreated. Indications: Meniscal root repair is indicated if possible, with the exception of patients who have diffuse Outerbridge 3-4 osteoarthritis of the ipsilateral compartment, those who are poor surgical candidates due to age or medical comorbidity, or in whom nonsymptomatic tears are found incidentally. Technique Description: Standard 2-portal arthroscopy is performed. Once a medial root tear has been identified and concomitant pathology has been addressed, we typically begin the repair by trephinating the deep medial collateral ligament with an 18-gauge needle to enhance visualization and avoid iatrogenic cartilage injury. Arthroscopic shaver is used to debride the meniscal root as needed. A meniscal root guide is introduced into the joint and an incision is made on the anteromedial tibia for outside-in drilling of a transosseous tunnel. Drilling is performed with a 5-mm retroreaming device, and a 10-mm socket is created. Nonabsorbable suture is then passed through the meniscus using a self-capture device in an inverted mattress configuration, following by 2 cinch stitches. The sutures are then shuttled into the transosseous tunnel, and the meniscal root is reduced and tensioned in full extension, with the sutures being fixated into a suture anchor on the anteromedial tibia. Results: A recent large systematic review of 1086 patients undergoing treatment of meniscal root tear via either debridement or nonoperative management compared with meniscal repair found that conversion to total knee arthroplasty occurred in 11% to 54% of those managed via debridement or nonoperative care versus 0% to 1% for those with root repair. Discussion/Conclusion: Currently, meniscal root repair offers the greatest improvement and lowest risk of conversion to arthroplasty following meniscal root tear. The present technique offers a durable repair that we believe combines ease of execution with decreased risk of suture pull-out, by creating a ripstop-type construct. Long-term outcome studies are needed for this and other root repair techniques.

Background: Surgical repair of chronic quadriceps tendon ruptures can be daunting, especially after failure of a prior repair. In this setting, tissue quality is usually poor, necessitating graft augmentation. In this video, we describe our technique for Achilles tendon allograft augmentation for revision quadriceps tendon repair. Indications: Failed quadriceps tendon repair defined as ongoing extensor mechanism deficit including patella baja, functional deficit, or palpable quadriceps defect with confirmed retear on advanced imaging. Technique Description: Patient is placed in the supine position, and a midline incision is extended to the tibial tubercle. Full thickness medial and lateral flaps are raised, nonviable scar tissue is excised, and suprapatellar adhesions are released to ensure full mobilization of the viable remnant quadriceps. A plane is then developed deep to the patellar tendon paratenon from proximal to distal. A reamer is used to prepare a socket just medial to the tibial tubercle. The calcaneal bone block of the Achilles allograft is fashioned to match the recipient site on the tibia with a sagittal saw. The graft is shuttled deep to the paratenon, and the bone plug is fixed to the tibia with an interference screw. Suture from the patellar anchors is then used to place 2 running Krackow stitches spanning the remnant quadriceps tendon proximally. The remnant tissue is subsequently reduced and tied with an anchor pull-through technique. The soft tissue component of the Achilles graft is laid over the repair and oversewn with free nonabsorbable suture. Patient is placed in a brace locked in extension for 6 weeks and allowed to be weight bearing as tolerated. Results: Long-term patient-reported outcomes of Achilles allograft reconstruction for revision extensor mechanism repairs are limited. Two studies of 17 reconstructions each reported this to be a reliable and durable option at a mean follow-up of 65 and 52 months, respectively. Discussion/Conclusion: Revision surgery for extensor mechanism deficits can be a challenging procedure. Our preference is to perform augmentation with Achilles allograft with bone plug fixation on the tibial side. This allows for augmentation of the entire extensor mechanism, as well as bone-to-bone healing on the tibial side.

Introduction: The threshold values needed to achieve MCID and PASS following HTO with or without concomitant procedures are not well known. Objectives: To determine values and variables predictive for achieving the minimally clinically important difference (MCID) and patient acceptable symptom state (PASS) of patient-reported outcome (PRO) scores following high tibial osteotomy (HTO) with or without associated restoration procedures for the correction of varus deformity. Methods: A prospectively collected HTO outcomes registry was retrospectively reviewed for patients who underwent HTO between 2001 and 2018. Collected PROs included International Knee Documentation Committee (IKDC), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Lysholm scores. A distribution-based approach was used to calculate MCID, and an anchor-based approach was used for the calculation of PASS. Results: Fifty-five patients were identified (n = 43 males; n = 12 females) with a mean age of 37.9 ± 9.0 years at surgery and average follow-up of 3.3 ± 3.1 years. The MCID and PASS for IKDC were calculated as 12.5 and 40.23, respectively. MCID and PASS values for each of the KOOS subscales were as follows: symptoms: 9.9 and 71.43; pain: 11.3 and 72.22; daily living: 12.0 and 77.94; sports: 16.0 and 40; quality of life: 15.1 and 56.25, respectively. Conclusions: Based on calculated values for MCID and PASS following HTO using IKDC and KOOS subscales, higher preoperative PROs, prior medial meniscectomy, higher BMI, concomitant ACL reconstruction and worker's compensation status were associated with failure to achieve clinically significant outcomes. Prior ACL reconstruction was found to be predictive of MCID for KOOS-symptoms.

Introduction: Few studies have reported on functional outcome and survivorship of simultaneous distal femoral osteotomy (DFO) and cartilage restoration techniques, including lateral femoral condyle osteochondral allograft transplantation (OCA). Objectives: The purpose of this investigation is therefore to evaluate short-term outcomes, mid-term outcomes, and satisfaction in patients receiving OCA and DFO. Methods: A registry of consecutive patients undergoing DFO with concomitant OCA between 2004 and 2017 was retrospectively reviewed. Patient records meeting inclusion criteria were reviewed to collect baseline demographic data; both pre- and postoperative radiographs were reviewed. Patients were contacted to complete postoperative outcome questionnaires. Subsequent surgical history and patient satisfaction were also assessed. The postoperative outcomes obtained were compared to prospectively collected preoperative outcome scores. Outcomes were compared using paired t-testing, with statistical significance defined as P< .05. Results: A total of 24 patients were identified, of which 17 (70.8%) completed follow-up at a mean of 7.13 years (range, 2-14.2 years) after surgery. At final follow-up, there were significant improvements in IKDC (P < .001), Lysholm (P = .001), and 4 of the KOOS subscales (ADL, P ≤ .001; Pain, P < .001; QOL, P < .001; Sport, P = .001). Two patients (10.5%) were considered treatment failures (one revision OCA and one graft debridement) at an average 1.48 years postoperatively. No patients underwent subsequent knee arthroplasty. All patients reported satisfaction with the surgery at final follow-up. Conclusion: In young, active patients with valgus deformity and lateral chondral defects of the knee, DFO with concomitant OCA can significantly improve functional scores compared to baseline at a minimum of 2 years after surgery.

Purpose: To define the time required to achieve the minimally clinically important difference (MCID), substantial clinical benefit (SCB) and patient acceptable symptomatic state (PASS) for isolated arthroscopic partial meniscectomy (APM), and define preoperative and intraoperative factors that predict both early and late achievement of the stated metrics. Methods: Patients who underwent isolated APM between 2014 and 2017 were retrospectively included. Patients without preoperative and 6-month patient-reported outcome measure scores, revision procedures, and significant concomitant procedures were excluded. The MCID, SCB, and PASS were calculated for knee-based patient-reported outcome measure scores using receiver operating curve analysis. Kaplan-Meier survival analysis established the time required to achieve MCID, SCB and PASS. Hazard ratios from multivariate Cox regression allowed for the isolation of demographic and intraoperative factors predictive of the delayed time required to achieve MCID, SCB and PASS. Results: A total of 126 patients (42.86% female, age: 48.9 ± 12.4 years) were included. Overall achievement rates ranged between 73.0% and 89.7% for MCID, 43.7% and 68.2% for SCB, and 50.8% and 68.3% for PASS. Median achievement time for MCID was 5.68-5.78 months, 5.73-6.05 months for SCB and 6.54-7.72 months for PASS. Multivariate Cox regression identified older age, workers’ compensation status, diabetes, and various tear types (i.e., longitudinal, transverse, bucket handle, complex) as predictors of early clinically significant outcome achievement (hazard ratio: 1.02-24.72), whereas subsequent steroid injection, higher preoperative scores and root and flap tears predicted delays in clinically significant outcome achievement (hazard ratio: 0.12-0.99). Conclusions: The majority of patients undergoing APM achieve benefit within 6 months of surgery, with diminishing proportions at later timepoints. Important factors for consideration of the the timeline of achieving clinically significant outcome include age, diabetes, workers’ compensation, preoperative score, and tear type. The timeline for achieving improvement that was established by this study may aid in setting patient expectations and designing future outcome studies involving APM. Study design: Level IV, Therapeutic Case Series.

Purpose: The purpose of this study was to evaluate the reliability and educational content of YouTube videos concerning injuries to the posterior cruciate ligament (PCL) of the knee. Methods: The first 50 videos specific to the PCL identified through the YouTube query posterior cruciate ligament were evaluated by a method of video selection demonstrated to be feasible in prior YouTube studies. Videos were classified by content and upload source. Video reliability was assessed using the Journal of the American Medical Association (JAMA) benchmark criteria (score range 0-5). Video educational content was assessed using the Global Quality Score (GQS) (range 0-4) and the PCL Score (PCLS) (score range 0-18). Analysis of variance was used to determine differences in video reliability and educational content quality based on video content and upload source. Multivariate linear regressions were used to identify predictors of video reliability and educational content quality. Results: The mean number of views per video was 50,477.9 ± 15,036. Collectively, the 50 videos were viewed 14,141,285 times. Video content was classified primarily as information about disease (62.0%). The most common upload sources were physicians (24.0%) and nonphysician health care providers (26.0%). Significant between-group interactions were found between video source and the JAMA score, with physicians and medical sources having significantly higher mean JAMA scores (P = 0.037). Videos uploaded by physicians were an independent positive predictor of greater JAMA scores (β:1.27; P = 0.008). Videos uploaded by a medical source (β:2.06; P = 0.038) were an independent positive predictor of a greater GQS. There were no independent associations between video content category or upload source and the PCLS. Conclusions: Videos concerning the PCL were frequently viewed on YouTube, but the educational quality and reliability of these videos were low. Clinical Relevance: Physicians and health care providers treating PCL pathology should take the initiative to counsel patients about which outside resources are reliable to better inform patients about their treatment decisions. With regard to YouTube videos specifically, providers should caution their patients that this source of information may be unreliable.

Purpose: To determine the biomechanical effect of limited lateral retinacular and capsular release on lateral patellar translation as a function of constant force at various knee flexion angles. Methods: Six pairs of bilateral cadaveric knee specimens (12 knees) were obtained from a tissue bank, dissected, and potted in a perfect lateral position based on fluoroscopy. A direct lateral force was applied to the patella through an eye screw in the midpoint of the lateral patella, and each knee underwent testing in the intact state and after lateral retinacular and capsular release. All knees were tested at 0°, 10°, 20°, 30°, 45°, 60°, and 90° of flexion using a custom-machined jig on a materials testing system with a 20-N lateral force applied to the patella. Patellar displacement was recorded and compared for each specimen. Results: Lateral displacement was significantly greater at all degrees of flexion for the lateral-release specimens than for an intact lateral retinaculum (P < .05). Compared with intact specimens, lateral-release specimens experienced 30% more translation at 0° of flexion and between 6% and 9% more lateral translation at 10° to 90° of flexion. Conclusions: Lateral retinacular and capsular release results in significantly increased lateral patellar translation at all flexion angles compared with intact specimens. This finding suggests that the lateral retinaculum may function as a significant restraint to lateral translation even with intact medial soft-tissue restraints. Clinical Relevance: Arthroscopic and open limited lateral retinacular releases should be performed with extreme caution when treating lateral patellar instability given the lateral retinaculum’s apparent role as a secondary restraint.

Introduction: We performed a survivorship analysis of patients treated with patellofemoral osteochondral allograft transplantation (OCA) using either a shell or plug technique and identified variables associated with graft failure. Methods: Consecutive patients at two institutions who underwent OCA of the patellofemoral compartment between March 1, 2001 to March 1, 2015, were retrospectively identified at minimum 2 years' follow-up. Demographic information, intraoperative findings, and postoperative data were collected. Patients were divided into two groups on the basis of surgical technique (plug group and shell group). Failure was defined as revision OCA, conversion to arthroplasty, or gross appearance of graft degeneration on second-look arthroscopy. Logistic regression analysis was performed to identify patient- and surgery-specific variables associated with survivorship. Results: Fifty patients were identified (36 women and 14 men; mean age 37.43 ± 8.87 years). Sixteen patients received plug allografts, whereas 34 received shell allografts. Forty percent of patients underwent a concomitant meniscal, ligamentous, malalignment, or chondral procedure. Five patients in the Plug Group (31.3%) underwent reoperation at a mean 1.37 ± 1.34 years, and 28 patients (82.4%) who received Shell OCA underwent reoperation at a mean 1.94 ± 1.92 years. Two patients in the plug group had graft failure at a mean 9.17 ± 0.93 years, whereas 13 patients in the shell group had graft failure at a mean 3.81 ± 2.78 years. Patients with plug allografts demonstrated 100% and 66% survival at 5 and 9.8 years, respectively. For the shell group, survivorship was 65.8% and 37% at 5 and 10.6 years, respectively. Increasing body mass index was associated with failure for the case series overall (odds ratio 1.33, P = .020). Traumatic cause was found to be protective of failure (odds ratio = 0.02, P = .035). Conclusions: Plug OCA of the patellofemoral compartment can be an efficacious procedure with quality mid-term outcomes. Shell OCA led to high failure rates at midterm outcomes. Increasing body mass index may predispose patients to failure, whereas traumatic cause of their lesion was associated with improved outcomes. Level of Evidence: Level IV, Therapeutic case series.