Editorial Commentary: The entry point-trochlear groove (EP-TG) angle measures lateralization of the proximal trochlear entry point in patients with patellar instability.

Patellar instability is a complex orthopedic condition, occurring at an incidence of 23.2 per 100,000 person-years, and resulting from a combination of osseous and soft tissue factors. Osseous abnormalities associated with patellar instability include trochlear dysplasia and a lateralized tibial tubercle. Evaluation of these factors includes dysplasia evaluation using the DeJour classification, and the tibial-tubercle-to-trochlear-groove distance (TT-TG) to evaluate relative lateralization of the tibial tubercle. Three-dimensional modeling has advanced the evaluation of complex trochlea geometry and patellar tracking. Evaluation of the TT-TG distance through flexion, dubbed the radial TT-TG (rTT-TG) distance, shows rTT-TG distances are notably larger than traditional TT-TG measurements, with increasing grade of dysplasia associated with a more pronounced difference between measurements. The entry point-trochlear groove (EP-TG) angle may help more accurately describe the morphology of the proximal trochlea and aid in planning or assessing osseous correction with a trochleoplasty. The EP-TG angle may also be of use as a variable to determine when an isolated medial patellofemoral ligament reconstruction (MPFLR) may fail and require osseous correction. A lateralized proximal trochlea entry point is associated with recurrent patellar instability.

Isolated Medial Patellofemoral Ligament Reconstruction Results in Lower Failure and Complication Rates than Isolated Trochleoplasty and Tibial Tubercle Osteotomy: A Systematic Review.

PURPOSE: To evaluate outcomes and complications of isolated medial patellofemoral ligament (MPFLR), tibial tubercle osteotomy (TTO), and trochleoplasty for management of patellar instability. METHODS: A query of Scopus, PubMed, Google Scholar, Cochrane CENTRAL Register of Controlled Trials, and the Cochrane Database of Systematic Reviews was performed in accordance with 2020 PRISMA guidelines. Included studies reported clinical outcome data after isolated MPFLR, TTO, or trochleoplasty for patellar instability with a minimum of 12 months of follow-up. Meta-analysis and data aggregation was not performed. RESULTS: Thirty-six studies (5 trochleoplasty, 14 TTO, and 18 MPFLR) consisting of 1,389 patients (114 trochleoplasty, 374 TTO, and 1,001 MPFLR) were included. Risk of bias was assessed with the Methodological Index for Non-Randomized Studies (MINORS) score which ranged from 11-12 in trochleoplasty, 10-18 in TTO, and 8-18 in MPFLR studies. Patient reported outcome measures including Lysholm Score (trochleoplasty: 51.1-71 to 71-95y; TTO: 57-63.3 to 84-98; MPFLR: 37.4-59.1 to 74-92.5), Kujala Score (trochleoplasty: 56-71 to 78-92; TTO: 48.6-68 to 78-92; MPFLR: 53.3-60 to 81.5-92), VAS Pain Scale (trochleoplasty: 52 to 25; TTO: 54-76 to 14-27; MPFLR: 29 to 17, out of 100), and Tegner Score (TTO: 3-4 to 3-4; MPFLR: 2.5-6 to 4.9-5) improved after all surgeries. Failure rates ranged from 0-33.3% after MPFLR, 0-30.8% after TTO, and 5.3-40% after trochleoplasty. Complication rates ranged from 0-14.7% after MPFLR, 1.6-58.3% after TTO, and 8-26.3% after trochleoplasty. CONCLUSIONS: Isolated MPFLR, TTO, or trochleoplasty may be effective treatment options for patellar stabilization. While failure rates were highest after isolated trochleoplasty and complication rates were highest after TTO, these procedures are not interchangeable as each addresses a specific pathology. LEVEL OF EVIDENCE: IV; Systematic Review of Level II-IV studies.

Revision and Conversion to Arthroplasty Are Low Among Adolescents Undergoing Meniscal Allograft Transplantation Using the Bridge-In-Slot Technique at Midterm Follow-Up.

PURPOSE: To report midterm outcomes after primary medial and lateral meniscal allograft transplantation (MAT) with fresh-frozen allografts implanted with the bridge-in-slot technique in the adolescent patient population. METHODS: Adolescent patients less than 18 years old at the time of primary MAT from 1999 to 2016 were retrospectively identified. International Knee Documentation Committee (IKDC) subjective form, Lysholm, and Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales scores were collected before surgery and at 1-year, 2-year, and a minimum 5-year follow-up. Thresholds for achieving clinically significant outcomes were calculated, and the proportion of patients achieving minimal clinically important difference (MCID), patient-acceptable symptomatic state (PASS), and substantial clinical benefit (SCB) was determined. Meniscus reoperation (partial, subtotal, or total meniscectomy, repair, or failure) and failure (revision MAT or conversion to arthroplasty) rates were determined. RESULTS: Forty-four (female n = 33; male n = 11) of 62 identified patients met inclusion criteria and were followed for a mean of 9.5 ± 3.8 years (range, 5.0-17.7). Lateral MAT was performed in most patients (n = 35/44 [80%]). Isolated MAT was performed in 27 (61%) patients. Common concomitant procedures included osteochondral allograft transplantation (32%), autologous chondrocyte implantation (18%), and anterior cruciate ligament reconstruction (14%). MCID, PASS, and SCB were achieved by patients at a minimum 5-year follow-up for IKDC (62%; 76%; 31%), Lysholm (62%; 79%; 23%), and KOOS questionnaires (Pain [65%; 81%; 41%], Symptoms [58%; 81%; 47%], Activities of Daily Living [53%; 77%; 35%], Sport [86%; 75%; 50%], and Quality of Life [59%; 81%; 59%]), respectively. Fourteen patients (32%) underwent reoperation at an average of 5.0 ± 4.3 years (range, 0.8-14.0) after MAT. Three (7%) patients met criteria for failure, requiring revision MAT an average of 3.8 ± 1.1 years (range, 2.8-4.9) after transplantation. No patients underwent arthroplasty. Overall survival free from failure at 1, 2, 5, and 10 years was 100%, 100%, 93%, and 93%, respectively. At the time of final follow-up, 80% of patients reported satisfaction with their current physical status. CONCLUSIONS: Primary MAT in adolescent patients resulted in significant and durable functional improvements at mid- to long-term follow-up. At an average of 9.5 years after surgery, meniscal reoperation rate was 32% whereas graft survival free of revision MAT was 93%. Adolescents undergoing MAT demonstrated similar functional outcomes and graft survivability when compared to available adult MAT literature. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Revision and Primary Meniscal Allograft Transplantations Provide Clinical Benefit at Mid-Term Follow-Up: A Matched-Cohort Analysis of Patient-Reported Outcomes, Reoperations, and Failures.

PURPOSE: To report the mid-term outcomes of patients who underwent revision meniscal allograft transplantation (RMAT) and compare survivorship free from reoperation and failure with a matched cohort of patients who underwent primary meniscal allograft transplantation (PMAT). METHODS: A retrospective review of prospectively collected data identified patients who underwent RMAT and PMAT between 1999 and 2017. A cohort of PMAT patients matched at a ratio of 2:1 with respect to age, body mass index, sex, and concomitant procedures served as the control group. Patient-reported outcome measures (PROMs) at baseline and at a minimum of 5 years postoperatively were collected. PROMs and the achievement of clinically significant outcomes were analyzed within groups. Graft survivorship free from meniscal reoperation and failure (arthroplasty or subsequent RMAT) was compared between cohorts using log-rank testing. RESULTS: During the study period, 22 RMATs were performed in 22 patients. Of these RMAT patients, 16 met the inclusion criteria (73% follow-up rate). The mean age of RMAT patients was 29.7 ± 9.3 years, and the mean follow-up period was 9.9 ± 4.2 years (range, 5.4-16.8 years). There were no differences between the RMAT cohort and the 32 matched PMAT patients with respect to age (P = .292), body mass index (P = .623), sex (P = .537), concomitant procedures (P ≥ .286), or baseline PROMs (P ≥ .066). The patient acceptable symptomatic state was achieved by the RMAT cohort for the subjective International Knee Documentation Committee score (70%), Lysholm score (38%), and Knee Injury and Osteoarthritis Outcome Score subscales (Pain [73%], Symptoms [64%], Sport [45%], Activities of Daily Living [55%], and Quality of Life [36%]). In the RMAT cohort, 5 patients (31%) underwent subsequent reoperation at a mean of 4.7 ± 2.1 years (range, 1.7-6.7 years) and 5 patients met the criteria for failure at a mean of 4.9 ± 2.9 years (range, 1.2-8.4 years). There were no significant differences in survivorship free from reoperation (P = .735) or failure (P = .170) between the RMAT and PMAT cohorts. CONCLUSIONS: At mid-term follow-up, most patients who underwent RMAT achieved the patient acceptable symptomatic state for the subjective International Knee Documentation Committee score and the Knee Injury and Osteoarthritis Outcome Score subscales of Pain, Symptoms, and Activities of Daily Living. Additionally, there were no differences in survival free from meniscal reoperation or failure between the PMAT and RMAT cohorts. LEVEL OF EVIDENCE: Level III, retrospective comparative cohort.

No significant difference in thick versus thin osteochondral flap trochleoplasty in the treatment of trochlear dysplasia: A systematic review.

PURPOSE: Trochleoplasty has become increasingly utilised to address patellar instability in the setting of severe trochlear dysplasia. There remains a paucity of literature on the outcomes of 'thick'- versus 'thin'-osteochondral flap trochleoplasty. The purpose of this study is to compare clinical and radiographic outcomes between patients with patellar instability with symptomatic trochlear dysplasia treated using a 'thick' versus 'thin' osteochondral flap trochleoplasty. METHODS: A systematic review and meta-analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using a PRISMA checklist. Quality assessment of final articles was conducted by two blinded reviewers. Articles were separated based on the use of a 'thick' versus 'thin' flap trochleoplasty. Data collection consisted of recording the following variables: patient demographics, indications for trochleoplasty, mean follow-up time, additional procedures performed during trochleoplasty, patient-reported outcome measures (PROMs), radiographic outcomes (tibial tubercle-trochlear groove [TT-TG] distance, Caton-Deschamps Index [CDI] and sulcus angle [SA]) and the incidence of any postoperative complications and patellar redislocation rates. RESULTS: A total of 24 studies, consisting of 927 patients, were identified as meeting inclusion criteria. A total of five papers described a 'thick' flap technique, while 19 papers described the use of a 'thin' flap technique. No significant difference in the mean improvement of Kujala scores was appreciated when comparing 'thick' versus 'thin' techniques (p > 0.05). Improvements in mean radiographic outcomes based on TT-TG, CDI and SA were observed in both 'thick' and 'thin' flap trochleoplasty groups. The overall redislocation rate was 0.35%. CONCLUSION: No significant difference in Kujala scores was observed in patients undergoing trochleoplasty utilising 'thick' versus 'thin' technique, while improvements in mean TT-TG, CDI and SA were noted in both technique groups, with an overall redislocation rate of 0.35%. LEVEL OF EVIDENCE: Level IV.

Concomitant Treatment of High-Grade Cartilage Lesions Mitigates Risk of Meniscal Allograft Transplant Failure.

PURPOSE: To identify frequently studied significant preoperative risk factors for meniscal allograft transplantation (MAT) failure. METHODS: Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines were used to conduct this systematic review. The database analysis was performed in May of 2022 and included PubMed, Embrace, and Cochrane. Studies between January 1, 2000, and January 1, 2021, were reviewed with search terms, including "meniscal," "meniscus," "transplantation," "transplant," and "allograft." Twenty-one full-text manuscripts met inclusion criteria of studies assessing preoperative risk factors for MAT failure defined as either clinical failure (Lysholm <65) or surgical failure (revision, removal, or conversion to knee arthroplasty). RESULTS: In total, 21 studies were included, comprising 47.6% with a Level of Evidence of Level III and 52.4% with Level of Evidence IV. The analysis involved 2,533 patients, and the mean final follow-up ranged from 2.2 to 20.0 years. The presence of high-grade cartilage defects was the only factor found predictive of MAT surgical failure in the majority of studies in which it was analyzed (5/7 studies, 71.4%). Four of the five studies that found high-grade cartilage defects to be a predictor of MAT surgical failure did not treat all cartilage lesions, while the 2 studies that found high-grade cartilage defects an insignificant predictor of MAT surgical failure treated all defects at the time of MAT. For clinical failure, no risk factors were predictive of MAT failure in the majority of studies, although smoking and concomitant ligamentous or realignment procedures were significant in 1 study. CONCLUSION: The presence of untreated high-grade cartilage appears to elevate the risk of surgical MAT failure; however, concomitant treatment of defects may mitigate their detrimental effect. There is no clear risk factor that consistently predicts clinical failure. Age, sex, BMI, knee compartment, time from prior meniscectomy, femorotibial alignment (after correction), concomitant cartilage procedure, and laterality do not routinely impact MAT failure. LEVEL OF EVIDENCE: Level IV, systematic review.

Suture Anchor-Based Quadriceps Tendon Repair May Result in Improved Patient-Reported Outcomes but Similar Failure Rates Compared to the Transosseous Tunnel Technique.

PURPOSE: The purpose of this study was to compare failure rates and patient-reported outcomes between transosseus (TO) suture and suture anchor (SA) quadriceps tendon repairs. METHODS: Following institutional review board approval, patients who underwent primary repair for quadriceps tendon rupture with TO or SA techniques between January 2009 and August 2018 were identified from an institutional database and retrospectively reviewed. Patients were contacted for satisfaction (1-10 scale), current function (0-100 scale), failure (retear), and revision surgeries; International Knee Documentation Committee (IKDC) score and Knee Injury and Osteoarthritis Outcomes Score (KOOS) were also collected to achieve a minimum of 2-year follow-up. RESULTS: Sixty-four patients (34 SA, 30 TO) were available by phone or e-mail at a mean of 4.81 ± 2.60 years postoperatively. There were 10 failures, for an overall failure rate of 15.6%. Failure incidence did not significantly differ between treatment groups (P = .83). Twenty-seven patients (47% of nonfailed patients) had completed patient-reported outcomes. The SA group reported higher subjective function (SA: 90 [85-100] vs TO: 85 [60-93], 95% CI of difference: -19.9 to -2.1 × 10-5, P = .042), final IKDC (79.6 [50.0-93.6] vs 62.1 [44.3-65.5], 95% CI of difference: -33.0 to -0.48, P = .048), KOOS Pain (97.2 [84.7-97.2] vs 73.6 [50.7-88.2], 95% CI of difference: -36.1 to -3.6 × 10-5, P = .037), Quality of Life (81.3 [56.3-93.8] vs 50.0 [23.4-56.3], 95% CI of difference: -50.0 to -6.2, P = .026), and Sport (75.0 [52.5-90.0] vs 47.5 [31.3-67.5], 95% CI of the difference: -45.0 to -4.1 × 10-5, P = .048). CONCLUSIONS: There is no significant difference in failure rate between transosseus and suture anchor repairs for quadriceps tendon ruptures (P = .83). Most failures occur secondary to a traumatic reinjury within the first year postoperatively. Despite the lack of difference in failure rates, at final follow-up, patients who undergo suture anchor repair may report significantly greater subjective function and final IKDC, KOOS Pain, Quality of Life, and Sport scores. LEVEL OF EVIDENCE: III, retrospective cohort study.

Consistent Indications and Good Outcomes Despite High Variability in Techniques for Two-Stage Revision Anterior Cruciate Ligament Reconstruction: A Systematic Review.

PURPOSE: To systematically review the current literature regarding the indications, techniques, and outcomes after 2-stage revision anterior cruciate ligament reconstruction (ACLR). METHODS: A literature search was performed using SCOPUS, PubMed, Medline, and the Cochrane Central Register for Controlled Trials according to the 2020 Preferred Reporting Items for Systematic Reviews and Meta Analyses statement. Inclusion criteria was limited to Level I-IV human studies reporting on indications, surgical techniques, imaging, and/or clinical outcomes of 2-stage revision ACLR. RESULTS: Thirteen studies with 355 patients treated with 2-stage revision ACLR were identified. The most commonly reported indications were tunnel malposition and tunnel widening, with knee instability being the most common symptomatic indication. Tunnel diameter threshold for 2-stage reconstruction ranged from 10 to 14 mm. The most common grafts used for primary ACLR were bone-patellar tendon-bone (BPTB) autograft, hamstring graft, and LARS (polyethylene terephthalate) synthetic graft. The time elapsed from primary ACLR to the first stage surgery ranged from 1.7 years to 9.7 years, whereas the time elapsed between the first and second stage ranged from 21 weeks to 13.6 months. Six different bone grafting options were reported, with the most common being iliac crest autograft, allograft bone dowels, and allograft bone chips. During definitive reconstruction, hamstring autograft and BPTB autograft were the most commonly used grafts. Studies reporting patient-reported outcome measures showed improvement from preoperative to postoperative levels in Lysholm, Tegner, and objective International Knee and Documentation Committee scores. CONCLUSIONS: Tunnel malpositioning and widening remain the most common indications for 2-stage revision ACLR. Bone grafting is commonly reported using iliac crest autograft and allograft bone chips and dowels, whereas hamstring autograft and BPTB autograft were the most used grafts during the second-stage definitive reconstruction. Studies showed improvements from preoperative to postoperative levels in commonly used patient reported outcomes measures. LEVEL OF EVIDENCE: Level IV, systematic review of Level I, III, and IV studies.

Patient-Specific Variables Associated with Failure to Achieve Clinically Significant Outcomes After Meniscal Allograft Transplantation at Minimum 5 Year Follow-Up.

PURPOSE: To determine the improvements in patient-reported outcome measures (PROMs) necessary to achieve minimal clinically important difference (MCID), patient-acceptable symptomatic state (PASS), and substantial clinical benefit (SCB) after primary meniscal allograft transplantation (MAT) at a minimum of 5-year follow-up, while identifying variables predictive of achieving clinically significant outcomes (CSOs). METHODS: A retrospective review was performed to identify patients undergoing primary MAT at a single institution from 1999 to 2016. Lysholm, International Knee Documentation Committee (IKDC), and Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales were collected before surgery and at a minimum of 5-year follow-up. A distribution-based approach was used to calculate MCID, whereas an anchor-based approach was used to calculate SCB and PASS. Multivariate logistic regression was performed to determine factors associated with CSO achievement. RESULTS: A total of 202 patients undergoing MAT (56% medial, 44% lateral) were included with a mean follow-up of 9.8 ± 4.1 years, age of 29.7 ± 8.5 years, and body mass index (BMI) of 26.5 ± 4.7. Thresholds for achieving MCID, PASS, and SCB, respectively, at a minimum 5-year follow-up for Lysholm (10.3, 74.5, 32.5), IKDC (12.1, 55.6, 29.1), and KOOS subscales questionnaires (Pain [11.0, 70.7, 25.1], Symptoms [11.0, 60.8, 19.6], Activities of Daily Living [10.5, 90.3, 17.9], Sport [16.2, 47.4, 37.5], and Quality of Life [13.6, 40.5, 37.3]) were calculated. Reduced odds of achieving MCID were associated with higher preoperative PROM scores, BMI, patient age, concomitant osteotomy, male sex, and worker's compensation (WC) status. Reduced odds of achieving PASS were associated with lower preoperative PROM scores, higher BMI (particularly ≥30), patient age, and WC status. Reduced odds of achieving SCB were associated with higher preoperative PROM scores and WC status. CONCLUSIONS: This study established the MCID, PASS, and SCB at 5-year minimum follow-up for the Lysholm score, IKDC, and KOOS subscales in patients who underwent MAT. Increased BMI and patient age, male sex, performance of concomitant osteotomy, WC status, and preoperative PROM scores were associated with failure to achieve CSOs after primary MAT at a minimum of 5-year follow-up. LEVEL OF EVIDENCE: Level IV, therapeutic study, retrospective case series.

Biphasic Interpositional Allograft for Rotator Cuff Repair Augmentation Is Safe in an Ovine Model.

PURPOSE: To perform a preclinical histologic assessment of a biphasic acellular interpositional cancellous allograft in an ovine model of rotator cuff repair (RCR) designed to better understand its safety profile and effects on tendon healing after RCR. METHODS: Thirty skeletally mature sheep with clinically normal shoulders with an artificially created degenerative infraspinatus tendon tear were randomized to control and treatment groups. Animals were euthanized at 3 weeks, 6 weeks, and 12 weeks. After gross dissection, rotator cuff specimens were fixed with formalin and polymerized for sectioning and staining. Blinded histologic scores evaluated inflammatory cell infiltrates, signs of degradation, particulate debris, collagen arrangement, neovascularization, and enthesis qualitative measures. RESULTS: There were no treatment specimens that exhibited histologic signs of a significant infection, inflammatory infiltrate, or foreign body reaction such as granuloma or fibrous capsule formation. Histologic scores in all categories were not significantly different at all time points, including the primary end point mean cumulative inflammatory score (control: 3.66 ± 1.21 vs treated: 4.33 ± 1.51, P = .42), when comparing the treatment and control RCR groups. In general, the degree of tendon healing and host tissue response was essentially equivalent between the 2 groups with observation of low overall levels of inflammation and progressive improvements in collagen organization, reduced tenocyte activity, and fibrocartilaginous enthesis reformation. CONCLUSIONS: This histologic study demonstrated the use of a biphasic interpositional allograft for RCR augmentation in an ovine model does not generate an inflammatory response or foreign body reaction. Use of the biphasic interpositional allograft resulted in a histological profile that was essentially equivalent to that of a standard RCR at 3-, 6-, and 12-week postoperative timepoints. These findings suggest that a biphasic interpositional allograft is safe for further clinical investigation in humans before broader clinical application. CLINICAL RELEVANCE: Patch augmentation of RCR is a popular technique that has shown clinical success in improving the likelihood of a successful repair in patients at elevated risk for retear. Newer augmentation technologies are being developed to address the biology at the interface between the bone and soft tissue where failure typically occurs.

Complication Rates After Medial Patellofemoral Ligament Reconstruction Range From 0% to 32% With 0% to 11% Recurrent Instability: A Systematic Review.

PURPOSE: To review the incidence of complications following primary medial patellofemoral ligament (MPFL) reconstruction for recurrent patellar instability. METHODS: A literature search was conducted by querying PubMed and Scopus databases from database inception through August 2022 according to the 2020 Preferred Reporting Items for Systematic Review and Meta-analysis guidelines using the terms "Medial Patellofemoral Ligament," "MPFL," "reconstruction," "patellar," and "instability." Inclusion criteria included studies reporting complications following primary MPFL reconstruction for recurrent patellar instability. Exclusion criteria consisted of studies reporting on patients undergoing concurrent osteotomy procedures, revision reconstruction, and biomechanical or anatomic studies. The incidence of specific complications was aggregated from the included studies. RESULTS: Twenty-eight studies, consisting of 1,478 patients (n = 1521 knees), with a mean age of 23.3 years (mean range, 19-34.3 years) were identified. The overall incidence of complications ranged from 0% to 32.3% of knees. Failure ranged from 0% to 10.7% of knees, whereas patellar fractures occurred in 0% to 8.3% of knees, primarily in patients treated with full-length transverse tunnel or 2-tunnel techniques. All patellar fractures occurred in patients with patellar tunnels ranging from 4.5 to 6.0 mm in diameter. The incidence of postoperative knee stiffness/range of motion deficit ranged from 0% to 20%. Persistent anterior knee pain, ranged from 0% to 32.3%. CONCLUSIONS: Complications following primary MPFL reconstruction ranged from 0% to 32.3% of knees, primarily consisting of residual anterior knee pain. Failure ranged from 0% to 10.7% of knees, whereas patellar fractures were reported in 0% to 8.3% of knees. Fractures primarily occurred with a full-length transverse tunnel or 2-tunnel techniques, whereas all fractures occurred with patellar tunnels ranging from 4.5 mm to 6.0 mm in diameter. LEVEL OF EVIDENCE: IV; Systematic Review of Level I-IV studies.

PROMIS physical function and pain perform poorly psychometrically in patients undergoing medial patellofemoral ligament reconstruction.

PURPOSE: The purpose of this study was to assess the validity, floor and ceiling effects, and dimensionality of PROMIS Physical Function (PF) and Pain compared to legacy patient reported outcome (PRO) measures in patients undergoing medial patellofemoral ligament (MPFL) reconstruction. METHODS: Patients who underwent MPFL reconstruction between 2018 to 2020 were retrospectively reviewed. Preoperatively, patients completed the IKDC, VR-12, Kujala, SF-12, KOOS JR, PROMIS PF and Pain surveys. Inter-survey convergence was assessed with Spearman correlations. Psychometric analysis included investigations of inter-survey convergent validity, intra-survey floor and ceiling effects, and Rasch analyses with person-item fit and iterative question elimination model fit testing. RESULTS: A total of 76 patients (mean age: 22.6 ± 8.4 years) who completed preoperative surveys were included (compliance: 91.7-96.2%). Preoperatively, age was significantly associated with both PROMIS PF (coefficient: - 0.291, P = 0.005) and Pain scores (coefficient: 0.294, P = 0.002). PROMIS PF had a Very Good correlation with IKDC and PROMIS Pain had a Very Good correlation with KOOS JR. Other correlations ranged from Poor to Good. No significant floor or ceiling effects were observed for any PRO. On iterative question elimination Rasch modelling, only two questions from PROMIS PF remained after 6 rounds of elimination while PROMIS Pain had no questions remaining after 3 rounds of elimination. CONCLUSION: Preoperative PROMIS PF and Pain provided only Fair to Good correlations with most legacy PROs. Although no significant floor and ceiling effects were observed, PROMIS PF and Pain did not perform well psychometrically in this population of patients undergoing MPFL reconstruction. These results suggest PROMIS questionnaires should be used with caution in this population, especially if used in isolation, when discussing clinical expectations with patients. The authors recommend continued use of legacy PROs specific to assessment of patellar instability and function that have established validity in patellar instability populations. LEVEL OF EVIDENCE: Level IV.

Long-term outcomes after osteochondral allograft transplantation to the humeral head.

BACKGROUND: Long-term outcomes of osteochondral allograft (OCA) transplantation to the humeral head have been sparsely reported in the literature. PURPOSE: To evaluate outcomes and survivorship of OCA transplantation to the humeral head in patients with osteochondral defects at a minimum of 10 years of follow-up. METHODS: A registry of patients who underwent humeral head OCA transplantation between 2004 and 2012 was reviewed. Patients completed pre and postoperative surveys including the American Shoulder and Elbow Surgeons score, Simple Shoulder Test, Short Form 12 (SF-12), and the visual analog scale. Failure was defined by conversion to shoulder arthroplasty. RESULTS: Fifteen of 21 (71%) patients with a minimum of ten year of follow-up (mean: 14.2 ± 2.40) were identified. Mean patient age was 26.1 ± 8.8 years at the time of transplantation and eight (53%) patients were male. Surgery was performed on the dominant shoulder in 11 of the 15 (73%) cases. The use of local anesthetic delivered via an intra-articular pain pump was the most often reported underlying etiology of chondral injury (n = 9; 60%). Eight (53%) patients were treated with an allograft plug, while seven (47%) patients were treated with a mushroom cap allograft. At final follow-up, mean American Shoulder and Elbow Surgeons (49.9 to 81.1; P = .048) and Simple Shoulder Test (43.1 to 83.3; P = .010) significantly improved compared to baseline. Changes in mean SF-12 physical (41.4 to 48.1; P = .354), SF-12 mental (57.5 to 51.8; P = .354), and visual analog scale (4.0 to 2.8; P = .618) did not reach statistical significance. Eight (53%) patients required conversion to shoulder arthroplasty at an average of 4.8 ± 4.7 years (range: 0.6-13.2). Kaplan-Meier graft survival probabilities were 60% at 10 years and 41% at 15 years. CONCLUSION: OCA transplantation to the humeral head can result in acceptable long-term function for patients with osteochondral defects. While patient-reported outcomes metrics were generally improved compared to baseline, OCA graft survival probabilities diminished with time. The findings from this study can be used to counsel future patients with significant glenohumeral cartilage injuries and set expectations about the potential for further surgery.

Editorial Commentary: Intraoperative Platelet-Rich Plasma Injections for Open-Wedge High Tibial Osteotomies Effectively Improve Clinical Outcomes and Minimal Medial Joint Space Width: An Orthobiologic Application.

Osteoarthritis is a significant cause of morbidity and mortality involving the knee joint, and high tibial osteotomy is becoming more commonly used to treat severe knee osteoarthritis. In addition, the best management and therapies to mitigate osteoarthritis symptoms and progression may include biologic injections, as we focus on more than just structural abnormalities but also on the inflammatory environment in the joint. These therapies include platelet-rich plasma, bone marrow aspirate concentrate, cell-based therapies, adipose-derived stromal cells, and amniotic suspension allografts. Recent research supports a promising therapy: combined high tibial osteotomy and intraoperative, intraarticular platelet-rich plasma injection.

Medial Patellofemoral Complex Reconstruction Techniques Are Not Equivalent at Lower Flexion in the Setting of Patella Alta: A Biomechanical Comparison.

PURPOSE: To (1) determine the effect of severe patella alta on lateral patellar displacement after medial patellofemoral ligament (MPFL) reconstruction and medial quadriceps tendon-femoral ligament (MQTFL) reconstruction and (2) determine whether lateral displacement significantly differs between MPFL and MQTFL reconstructions in the setting of severe patella alta (Caton-Deschamps Index [CDI] of 1.6). METHODS: Eight cadaveric specimens were included. High-tensile strength suture was used to create a model of adjustable patellar height. Patellar height was set using fluoroscopy to CDI ratios of 1.0 (normal) and 1.6 (alta). Specimens underwent testing (1) with MPFL reconstruction, (2) with MQTFL reconstruction, and (3) in a medial patellofemoral complex (MPFC)-deficient control state, in randomized order, at both CDI settings: 1.0 and 1.6. Lateral patellar translation was measured at 0°, 10°, 20°, 30°, 45°, 60°, and 90° of knee flexion with 10 N of laterally directed load. RESULTS: At a CDI of 1.6, MPFL reconstruction showed significantly lower lateral displacement than MQTFL reconstruction at 0° and 20°. When compared with MPFC-deficient controls at a CDI of 1.6, MPFL reconstruction showed significantly lower displacement at 0° and 20° whereas MQTFL reconstruction was not significantly different at any degree of flexion. CONCLUSIONS: In the setting of severe patella alta (CDI of 1.6), MPFL reconstruction results in less lateral patellar displacement than MQTFL reconstruction at 0° and 20° of knee flexion. At higher flexion angles (≥30°), there is no difference between the 2 reconstruction techniques and the CDI no longer has an effect. At a CDI of 1.0, MPFL reconstruction shows lower displacement than MQTFL reconstruction in full extension only. Surgeons performing MPFC reconstruction should evaluate patients for patella alta and consider patellar height when deciding on the reconstruction technique. CLINICAL RELEVANCE: This study suggests that MQTFL reconstruction may be less stable than MPFL reconstruction in the setting of patella alta, without other known pathoanatomic factors, at early knee flexion angles. Patellar height should be considered when choosing the appropriate reconstruction technique in the absence of a distalization procedure.

Concomitant Meniscotibial Ligament Reconstruction Decreases Meniscal Extrusion Following Medial Meniscus Allograft Transplantation: A Cadaveric Analysis.

PURPOSE: To compare meniscal extrusion (ME) following medial meniscus allograft transplantation (MMAT) with and without meniscotibial ligament reconstruction (MTLR). METHODS: Ten cadaveric knees were size-matched with meniscus allografts. MMAT was performed via bridge-in-slot technique. Specimens were mounted in a testing system and ME was assessed via ultrasound anterior, directly over, and posterior to the medial collateral ligament at the joint line under 4 testing conditions: (1) 0° flexion and 0 newtons (N) of axial load, (2) 0° and 1,000 N, (3) 30° and 0 N, and (4) 30° and 1,000 N. For each condition, "mean total extrusion" was calculated by averaging measurements at each position. Next, MTLR was performed using 2 inside-out sutures through the remnant allograft meniscotibial ligament and secured to the tibia using anchors. The testing protocol was repeated. Differences in ME between MMAT alone versus MMAT + MTLR were examined. Within-group differences between the measurement positions, loading states, and flexion angles also were assessed. RESULTS: "Mean total extrusion" was greater following MMAT alone (2.56 ± 1.23 mm) versus MMAT + MTLR (2.14 ± 1.07 mm; P = .005) in the loaded state at 0° flexion. ME directly over the MCL was greater following MMAT alone (3.51 ± 1.00 mm) compared with MMAT + MTLR (2.93 ± 0.79 mm; P = .054). Posteriorly, in the loaded state at 0°, ME was greater following MMAT alone (2.43 ± 1.10 mm) compared with MMAT + MTLR (1.96 ± 0.99 mm; P = .010). In all conditions, ME was greater in the loaded state versus the unloaded state. CONCLUSIONS: Following MMAT, the addition of MTLR significantly reduced overall ME when compared with isolated MMAT during loading at 0° of flexion in a cadaveric model; given the small absolute values of change in extrusion, clinical significance cannot be gleaned from these findings. CLINICAL RELEVANCE: During medial meniscus allograft transplantation, augmentation with meniscotibial ligament reconstruction may limit meniscal extrusion and improve the biomechanical milieu of the knee joint following transplant.

Bone Marrow Aspirate Concentrate Augmentation May Accelerate Allograft Ligamentization in Anterior Cruciate Ligament Reconstruction: A Double-Blinded Randomized Controlled Trial.

PURPOSE: To assess the effect of bone marrow aspiration concentrate (BMAC) augmentation on clinical outcomes and magnetic resonance imaging (MRI) findings in anterior cruciate ligament (ACL) reconstruction (ACLR) with bone-patellar tendon-bone (BTB) allografts. METHODS: A double-blinded, randomized controlled trial was conducted on 80 patients undergoing ACL reconstruction using BTB allografts. Patients were randomized to 2 groups: (1) bone marrow aspirate was collected from the iliac crest, concentrated, and approximately 2.5 mL was injected into the BTB allograft, or (2) a small sham incision was made at the iliac crest (control). MRI was performed at 3 months and 9 months postoperatively to determine the signal intensity ratio of the ACL graft. RESULTS: Seventy-three patients were available for follow-up at 1-year postoperatively (36 BMAC, 37 control). International Knee Documentation Committee (IKDC) scores were significantly greater in the BMAC group versus the control at the 9-month postoperative period (81.6 ± 10.5 vs 74.6 ± 14.2, P = .048). There was no significant difference in the proportion of patients who met the minimal clinically important difference for IKDC between the BMAC and control groups at 9 months (89% vs 85%; P = .7). Three months postoperatively, signal intensity ratio of the inferior third of the ACL graft was significantly greater in the BMAC group versus the control group (3.2 ± 2.2 vs 2.1 ± 1.5; P = .02). CONCLUSIONS: Patients who received BMAC augmentation of the BTB allograft during ACL reconstruction demonstrated greater signal intensity scores on MRI at 3 months, suggesting increased metabolic activity and remodeling, and potentially accelerated ligamentization. Additionally, patients in the BMAC group had greater patient-reported outcomes (IKDC) at 9 months postoperatively when compared with those who underwent a standard surgical procedure. There was no significant difference in the proportion of patients who met the minimal clinically important difference for IKDC between the BMAC and control groups at 9 months, suggesting limited clinical significance at this time point. LEVEL OF EVIDENCE: I, randomized control trial.

Do Outcomes of Meniscal Allograft Transplantation Differ Based on Age and Sex? A Comparative Group Analysis.

PURPOSE: To analyze the effect of patient age, sex, and associated preoperative factors on patient-reported outcome (PRO) measures and graft survival following primary meniscal allograft transplantation (MAT). METHODS: A prospectively collected database was retrospectively reviewed to identify patients who underwent primary MAT with a minimum of 2 years of follow up between 1999 and 2017. Demographic, intraoperative, and postoperative outcome data were collected for each patient. Postoperative outcomes were stratified based on age and sex, and comparative statistical analysis was performed between sexes, both >40 and <40. RESULTS: A total of 238 patients underwent primary MAT during the study period, of which 212 patients (mean age, 28.5 ± 9.0 years; range, 15.01-53.67 years) met the inclusion criteria with a mean follow-up of 5.1 ± 3.4 years (range 2.0-15.9 years). At final follow-up, patients ≥40 and <40 years of age demonstrated statistically significant improvements in nearly all PRO scores (P < .05 for both groups). There were no significant differences between either group for achievement of minimal clinically important difference for International Knee Documentation Committee (P = .48) or Knee Injury and Osteoarthritis Outcome Score symptoms (P = .76). Because of insufficient numbers, a statistically significant difference could not be demonstrated in reoperation rate (≥40: 1.49 ± 1.77 years, <40: 1.87 ± 1.98 years, P = .591), failure rate (≥40: 7/32 [21.9%], <40: 19/180 [10.6%], P = .072), or complication rate (≥40: 2/32 [6.3%], <40: 12/180 [6.7%], P = .930) based on age. Both sexes showed a significant improvement in PROs, whereas female patients were more likely to undergo revision surgery (P = .033), with no significant differences based on time to reoperation, failure, or complication rates. CONCLUSIONS: PROs similarly improved following MAT in both patients aged ≥40 and those <40 at final follow-up with no significant differences in minimal clinically important difference achievement rate, complication rate, reoperation rate, time to reoperation, or failure rate between groups. Female patients may be more likely to undergo revision surgery after MAT. LEVEL OF EVIDENCE: III; therapeutic retrospective comparison study.

Two-Year Clinical Outcomes and Survivorship After Isolated Biceps Tenodesis.

PURPOSE: The purpose of this study was to evaluate clinical outcomes and survivorship of isolated biceps tenodesis (BT) at a minimum of 2 years and to identify patient-specific factors associated with these outcomes in patients undergoing BT without concomitant rotator cuff repair (RCR). We hypothesized that patient-reported outcomes would be significantly improved on American Shoulder and Elbow Surgeons Survey (ASES) and Single Assessment Numeric Evaluation (SANE), with a high rate of survivorship (>90%) at 2-year follow-up. METHODS: A retrospective review of an institutional registry was performed to identify patients who underwent BT from July 2016 to December 2017. Patients >18 years old who underwent an open or arthroscopic BT procedure using an interference screw, button, or anchor for underlying bicipital pathology, without a concomitant RCR or shoulder arthroplasty, and were a minimum of 2 years postoperative were included. Patients were administered ASES and SANE questionnaires preoperatively and at final follow-up. Survivorship was evaluated using Kaplan-Meier analysis. Failure was defined as any patient who underwent reoperation related to the index surgery. RESULTS: A total of 110 patients (mean ± standard deviation age, 48.60 ± 12.14 years) who underwent isolated BT with a follow-up of 24.90 ± 3.95 months were included in analysis. There was a significant improvement in ASES and SANE at final follow-up (P < .001), with 81% to 84% of patients achieving minimal clinically important difference (MCID), 72% to 82% achieving substantial clinical benefit (SCB), and 72% to 80% achieving patient-acceptable symptom state (PASS). Worker's Compensation (WC) patients had a decreased likelihood of achieving PASS on ASES (P = .015) and SANE (P = .012). Four cases were deemed failures (3 revision BTs and 1 capsular debridement) at 15.09 ± 9.57 months. WC did not have a significant effect on likelihood of BT failure. CONCLUSION: Biceps tenodesis provided significant clinical improvement and high rates of survivorship 2 years postoperatively. WC was associated with a decreased likelihood of achieving PASS. These results support the continued use of isolated BT for treating biceps pathology. LEVEL OF EVIDENCE: IV, case series.

Patients Follow 3 Different Rate-of-Recovery Patterns After Anterior Cruciate Ligament Reconstruction Based on International Knee Documentation Committee Score.

PURPOSE: To determine whether subgroups of patients exist based on the rate-of-recovery pattern of International Knee Documentation Committee (IKDC) scores after anterior cruciate ligament reconstruction (ACLR) and to determine clinical predictors for these subgroups. METHODS: Patients who underwent primary or revision ACLR at a single institution from January 2014 to January 2019 were identified. Latent class growth analyses and growth mixture models (GMMs) with 1 to 6 classes were used to identify subgroups of patients based on functional rate-of-recovery patterns by use of preoperative, 1-year postoperative, and 2-year postoperative IKDC scores. RESULTS: A total of 245 patients who underwent ACLR were included in the analysis. A 3-class GMM was chosen as the final model after 6 different models were run. Class 1, showing improvement from preoperatively to 1-year follow-up, with sustained improvement from 1 to 2 years postoperatively, constituted 77.1% of the study population (n = 189), whereas class 2, showing functional improvement between 1- and 2-year follow-up, was the smallest class, constituting 10.2% of the study population (n = 25), and class 3, showing slight improvement at 1-year follow-up, with a subsequent decline in IKDC scores between 1- and 2-year follow-up, constituted 12.7% of the study population (n = 31). Revision surgery (P = .005), a psychiatric history (P = .025), preoperative chronic knee pain (P = .024), and a subsequent knee injury within the follow-up period (P = .011) were the predictors of class 2 and class 3 rate-of-recovery patterns. Patient demographic characteristics, graft type, and concomitant ligament, meniscus, or cartilage injury at the time of surgery were not associated with the different recovery patterns described in this study. CONCLUSIONS: Patients may follow different rate-of-recovery patterns after ACLR. By use of the GMMs, 3 different rate-of-recovery patterns based on IKDC scores were identified. Although most patients follow a more ideal rate-of-recovery pattern, fewer patients may follow less favorable patterns. Revision surgery, a history of psychiatric illness, preoperative chronic knee pain, and a subsequent knee injury within the follow-up period were predictive of less favorable rate-of-recovery patterns. LEVEL OF EVIDENCE: Level III, retrospective cohort study.