Editorial Commentary: Stabilize the Patella to Achieve Functional Gain but Don't Neglect the Cartilage That May Cause Long-Term Pain! Trochlear Dysplasia Plays a Role in Both.

While trochlear dysplasia is commonly discussed as a major risk factor for recurrent patellar instability, it also has a strong relationship with the development of patellofemoral cartilage lesions. Patellofemoral instability frequently occurs in teens and young adults, and the high prevalence of associated cartilage damage unfortunately sets patients up for the progression of degenerative changes of the patellofemoral joint at an early age. The judicious use of magnetic resonance imaging can help identify the presence of chondral lesions, allowing for urgent management of associated osteochondral fractures or open discussions and patient education about the possibility of performing a cartilage restoration procedure concurrently with patellar stabilization surgery. The location and presence of patellofemoral chondral lesions should be considered when contemplating the concurrent use of tibial tubercle osteotomy as part of the patellar stabilization procedure.

Male Sex, Western Ontario Shoulder Instability Index Score, and Sport as Predictors of Large Labral Tears of the Shoulder: A Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability Cohort Study.

PURPOSE: To identify factors predictive of a large labral tear at the time of shoulder instability surgery. METHODS: As part of the Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability cohort, patients undergoing open or arthroscopic shoulder instability surgery for a labral tear were evaluated. Patients with >270° tears were defined as having large labral tears. To build a predictive logistic regression model for large tears, the Feasible Solutions Algorithm was used to add significant interaction effects. RESULTS: After applying exclusion criteria, 1235 patients were available for analysis. There were 222 females (18.0%) and 1013 males (82.0%) in the cohort, with an average age of 24.7 years (range 12 to 66). The prevalence of large tears was 4.6% (n = 57), with the average tear size being 141.9°. Males accounted for significantly more of the large tears seen in the cohort (94.7%, P = .01). Racquet sports (P = .01), swimming (P = .02), softball (P = .05), skiing (P = .04), and golf (P = .04) were all associated with large labral tears, as was a higher Western Ontario Shoulder Instability Index (WOSI; P = .01). Age, race, history of dislocation, and injury during sport were not associated with having a larger tear. Using our predictive logistic regression model for large tears, patients with a larger body mass index (BMI) who played contact sports were also more likely to have large tears (P = .007). CONCLUSIONS: Multiple factors were identified as being associated with large labral tears at the time of surgery, including male sex, preoperative WOSI score, and participation in certain sports including racquet sports, softball, skiing, swimming, and golf. LEVEL OF EVIDENCE: I, prognostic study.

Safety and early results of Subchondroplasty® for the treatment of bone marrow lesions in osteoarthritis: a systematic review.

PURPOSE: Subchondroplasty® is a novel minimally invasive procedure for painful subchondral bone marrow lesions (BMLs). The aim of this systematic review was to characterize the clinical outcomes of the Subchondroplasty® procedure, a novel minimally invasive procedure for the treatment of BMLs. The hypothesis tested was that patients experience improvements in pain and functional outcomes following the Subchondroplasty® procedure. METHODS: MEDLINE, Embase, Web of Science, and Clinicaltrials.gov were searched from database inception to search date (June 10, 2020) for all clinical studies which discussed Subchondroplasty®. Two reviewers independently screened 45 unique results and 17 studies were included in the final analysis. Data were collected regarding patient demographics, indications, pain, functional scores, conversion to TKA, and complications of the procedure. RESULTS: All but one study were level IV evidence; the mean MINORS score was 9 ± 2. There were 756 patients included, 45.1% were female, and the mean age was 54 years (range 20-85). Thirteen studies investigated the effect Subchondroplasty® to the knee, while four studied the impact on the foot and ankle. Median length of follow-up was 12 months. The most common indication for Subchondroplasty® was joint pain with corresponding BML. Major contraindications to Subchondroplasty® included severe OA, joint instability, and malalignment. Mean pain score on visual analogue scale (VAS) prior to Subchondroplasty® was 7.8 ± 0.6, but decreased to 3.4 ± 0.7 postoperatively. All studies investigating functional scores reported improvement following Subchondroplasty® (IKDC 31.7 ± 1.9-54.0 ± 4.2 and KOOS 38.1 ± 0.6-70.0 ± 4.1). There were consistently high levels of patient satisfaction; 87 ± 8% of patients would be willing to undergo the procedure again. Seven cases of complications were reported, most seriously osteomyelitis and avascular necrosis. Conversion to knee arthroplasty ranged from 12.5 to 30% with length of follow-up ranging from 10 months to 7 years. CONCLUSIONS: Existing low-quality studies show Subchondroplasty® to benefit patients with BMLs through reduction in pain and improvement in function, along with a high degree of satisfaction following the procedure. The low short-to-medium term conversion rate to arthroplasty suggests that Subchondroplasty® may play a role in delaying more invasive and expensive procedures in patients with BMLs. Subchondroplasty® is a novel procedure that has promising initial findings, but requires further high-quality, comparative studies with long-term follow-up to better understand the outcomes of the procedure and impact clinical practice recommendations. LEVEL OF EVIDENCE: Systematic Review of Level III and IV Studies, Level IV.

Influence of Graft Source on Postoperative Activity and Joint Laxity in Posterior Cruciate Ligament Reconstruction: A Systematic Review.

PURPOSE: To compare the clinical and functional outcomes of allograft and autograft reconstruction in patients with posterior cruciate ligament (PCL) deficiency. METHODS: The MEDLINE, Embase, and Cochrane Library databases were used to identify all relevant articles. Clinical outcomes including International Knee Documentation Committee, Tegner, and Lysholm scores; joint laxity; and posterior tibial displacement were evaluated. RESULTS: Among the 145 unique articles identified during the title screening, 25 studies published between 2002 and 2016 with a combined population of 900 patients were deemed eligible for inclusion in the review. Of the 900 patients, 603 were treated with autograft and 297 were treated with allograft PCL reconstruction. Five of the included studies directly compared autograft and allograft PCL reconstruction. Most studies found postoperative functional outcomes and joint laxity to improve postoperatively regardless of graft source. With only 1 exception, the included comparative studies found no significant postoperative difference in any of the functional outcome scores between patients treated with allograft and those treated with autograft. Two comparative studies found autograft reconstruction to result in significantly less posterior laxity than in the allograft group, whereas 2 comparative studies found no significant difference in posterior laxity between the 2 groups. CONCLUSIONS: PCL reconstruction results in improved functional outcome scores and joint laxity regardless of graft source. Current studies suggest there is no significant difference in postoperative functional outcomes between patients treated with autograft and those treated with allograft. Patients treated with autograft have donor-site morbidity that is not associated with allograft reconstruction. Some evidence suggests that autograft reconstruction may result in reduced posterior laxity relative to allograft reconstruction. The magnitude of this finding, however, may not be clinically significant. Our review found that decision making based on the current literature is at high risk of potential bias. LEVEL OF EVIDENCE: Level IV, systematic review of Level I to IV studies.

Subchondral Bone Alignment in Osteochondral Allograft Transplants for Large Oval Defects of the Medial Femoral Condyle: Comparison of Lateral versus Medial Femoral Condyle Donors.

OBJECTIVE: Supply-demand mismatch of medial femoral condyle (MFC) osteochondral allografts (OCAs) remains a rate-limiting factor in the treatment of osteochondral defects of the femoral condyle. Surface contour mapping was used to determine whether a contralateral lateral femoral condyle (LFC) versus ipsilateral MFC OCA differs in the alignment of donor:native subchondral bone for large osteochondral defects of the MFC. DESIGN: Thirty fresh-frozen human femoral condyles were matched by tibial width into 10 groups of 3 condyles (MFC recipient, MFC donor, and LFC donor) each for 3 cartilage surgeons (90 condyles). The recipient MFC was imaged using nano-computed tomography scan. Donor oval grafts were harvested from each matched condyle and transplanted into a 17 mm × 36 mm defect created in the recipient condyle. Following the first transplant, the recipient condyle was imaged and superimposed on the native condyle nano-CT scan. The donor plug was removed and the process repeated for the other donor. Surface height deviation and circumferential step-off height deviation were compared between native and donor subchondral bone surfaces for each transplant. RESULTS: There was no statistically significant difference in mean subchondral bone surface deviation (LFC = 0.87 mm, MFC = 0.76 mm, P = 0.07) nor circumferential step-off height (LFC = 0.93 mm, MFC = 0.85 mm, P = 0.09) between the LFC and MFC plugs. There were no significant differences in outcomes between surgeons. CONCLUSIONS: There were no significant differences in subchondral bone circumferential step-off or surface deviation between ipsilateral MFC and contralateral LFC oval-shaped OCAs for 17 mm × 36 mm defects of the MFC.

Radiologic review of knee dislocation: from diagnosis to repair.

OBJECTIVE: This imaging-based article systematically reviews traumatic knee dislocations. After completion, the reader should be familiar with the definition, epidemiology, cause, and classification schemes associated with these injuries, as well as the importance of timely diagnostic imaging and an accurate, detailed description of findings, particularly as it relates to MRI interpretation. Finally, information our orthopedic surgical colleagues consider critical for the preoperative planning and reconstruction of the multiple ligament knee injury will be discussed. CONCLUSION: Although uncommon, traumatic knee dislocations are an important potentially limb-threatening injury, which if not emergently recognized and appropriately managed, can result in significant patient morbidity, joint dysfunction, chronic pain, and long-term disability. A radiologist familiar with the imaging appearance and potential neurovascular complications associated with these injuries can play an integral role in the multidisciplinary team that manages this increasingly recognized clinical entity.

Updating Recommendations for Rehabilitation after ACL Reconstruction: a Review.

OBJECTIVE: To review recent evidence in order to update previous systematic reviews on methods of rehabilitation after anterior cruciate ligament (ACL) reconstruction. DATA SOURCES: PubMed, Embase, and the Cochrane Controlled Trials Register were searched for the period January 2006 to December 2010, using terms related to ACL, rehabilitation, and randomized controlled trial (RCT). The search was done in triplicate, and the results reconciled (85 studies identified). STUDY SELECTION: Relevant studies in English that were peer-reviewed RCTs or prospective comparative studies evaluating methods of ACL rehabilitation were included (n = 29). Evidence was evaluated by all 3 authors using the CONSORT criteria. DATA EXTRACTION: The data extracted included number of patients, ACL reconstruction method, randomization method, intervention, length of, and loss to, follow-up, outcomes assessed, bias, and findings. The review included evidence on postoperative bracing, accelerated rehabilitation, home-based rehabilitation, proprioceptive and neuromuscular training, and miscellaneous topics that were investigated by single trials. MAIN RESULTS: In 6 studies of postoperative bracing, no study found a clinically significant benefit of bracing or of restricted range of knee motion for pain control, knee laxity, or rehabilitation. Postoperative treatment without the use of a brace was not associated with less favorable outcomes. In 5 studies of accelerated strengthening, beginning eccentric quadriceps strengthening and isokinetic hamstring strengthening 2 weeks after ACL surgery improved or accelerated strength gains. Immediately postoperative weight-bearing, range of knee motion from 0° to 90° of flexion, and strengthening with closed-chain exercises were probably all safe. Home-based rehabilitation was evaluated in 2 studies. One study demonstrated that this intervention was at least as successful as a standard accelerated program over the long term. The other study included very low compliance expectations and other methodologic problems that precluded a useful assessment of benefit. Nine trials of neuromuscular strengthening (including perturbation, vibration, and/or balance training by various means) compared with strength, traditional rehabilitation, or placebo found some small short-term benefits to proprioceptive training and no harm from any of the treatments. Vibration training in addition to other strengthening may lead to faster proprioceptive recovery but the benefits to overall functional outcome are less clear. A study of vitamin C and E supplementation found a correlation between higher presurgery vitamin C levels and greater strength at 3 months, but this strength increase was not related to postsurgical vitamin C supplementation. Hyaluronic acid injection at 8 weeks improved ambulation and peak torque more than other doses or placebo, but poor outcomes in the control group raise questions about the quality of the standard rehabilitation program. Running interval training and continuous active motion had unclear effects. Using the uninjured leg for single-leg cycling prevented the usual loss of aerobic fitness in the postoperative period. Preoperative and postoperative video instruction decreased expectations of pain and increased self-efficacy although it made no difference to performance. CONCLUSIONS: The review of rehabilitation interventions after ACL reconstruction suggests that both accelerated and home-based rehabilitation, neuromuscular training programs, hyaluronic acid injection, and single (uninjured) leg cycling may be beneficial. Preoperative and postoperative informational videos may be valuable for psychological well-being. Insufficient evidence was found to recommend bracing.

Comparison of manipulation and arthroscopic capsular release for adhesive capsulitis: a systematic review.

BACKGROUND: It is currently unclear as to whether there is a difference in the clinical effectiveness of an arthroscopic capsular release compared to a manipulation under anaesthesia (MUA) in patients with recalcitrant idiopathic adhesive capsulitis. METHODS: A systematic review was performed using computerized keyword searches of MEDLINE, EMBASE, CINAHL, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews. Two reviewers independently performed searches and article reduction. Studies that reported outcomes data following either a manipulation under regional or general anaesthesia or an arthroscopic capsular release in patients with idiopathic adhesive capsulitis were included. Data on clinical measures of shoulder range of motion and subjective outcome measures were extracted and summarized. RESULTS: Twenty-two studies (21 studies provided level IV evidence) including 989 patients were included resulting in a comparison of 9 MUA and 17 capsular release groups. Patients were 60% female with a median age of 52 years old (range, 24-91 years). Median duration of symptoms and follow-up were 9 months (range, 3-50) and 35 months (range, 3-189), respectively. There were minimal differences in the median changes in abduction, flexion, and external rotation range of motion (ROM), and final Constant score between the MUA and capsular release groups. CONCLUSION: The quality of evidence available is low and the data available demonstrate little benefit for a capsular release instead of, or in addition to, an MUA. A high quality study is required to definitively evaluate the relative benefits of these procedures.

Intra- and inter-rater reliability of the detection of tears of the supraspinatus central tendon on MRI by shoulder surgeons.

BACKGROUND: The purpose of this study was to determine the intra- and inter-rater reliability of detecting full- and partial-thickness tears of the supraspinatus intramuscular central tendon on magnetic resonance imaging (MRI) by orthopaedic shoulder surgeons. Full-thickness tears of this tendon have previously been associated with the failure of nonsurgical management of rotator cuff tears. METHODS: Shoulder MRIs from 40 patients entered into a prospective rotator cuff disease database were independently reviewed by two musculoskeletal (MSK) radiologists in order to determine if there was a partial- or full-thickness tear of the supraspinatus central tendon. The MRIs were randomly sorted and distributed to 16 fellowship-trained shoulder surgeons. The surgeons then similarly diagnosed each patient. After a 1-month interval, surgeons repeated the evaluation with the same set of randomly reordered MRIs. Surgeon intra- and inter-rater reliability was determined with the kappa statistic. Agreement and inter-rater reliability were also determined between the shoulder surgeons and MSK radiologists. RESULTS: For full-thickness tears, the intra-rater reliability was excellent (0.86 ± 0.1, 95% confidence interval (CI): 0.81, 0.91) and the agreement was 93.4% ± 4.6, 95% CI: 91.1, 95.8. Inter-rater reliability for both rounds was also excellent (0.77 and 0.74). The agreement between the shoulder surgeons and MSK radiologists was 92.9% ± 3.9, 95% CI: 90.9, 94.9, and the kappa was 0.85 ± 0.08, 95% CI: 0.81, 0.89. Including partial-thickness tears resulted in agreement of 65-92% and kappa values of 0.59-0.72. CONCLUSION: The reliability for the MRI detection of full thickness tears of the supraspinatus central tendon among shoulder surgeons and between shoulder surgeons and MSK radiologists was excellent.

Cartilage thickness mismatches in patellar osteochondral allograft transplants affect local cartilage stresses.

Osteochondral allograft implantation is a form of cartilage transplant in which a cylindrical graft of cartilage and subchondral bone from a donor is implanted into a patient's prepared articular defect site. No standard exists for matching the cartilage thickness of the donor and recipient. The goal of this study was to use finite element (FE) analysis to identify the effect of cartilage thickness mismatches between donor and recipient cartilage on cartilage stresses in patellar transplants. Two types of FE models were used: patient-specific 3D models and simplified 2D models. 3D models highlighted which geometric features produced high-stress regions in the patellar cartilage and provided ranges for the parameter sweeps that were conducted with 2D models. 2D models revealed that larger thickness mismatches, thicker recipient cartilage, and a donor-to-recipient cartilage thickness ratio (DRCR) < 1 led to higher stresses at the interface between the donor and recipient cartilage. A surface angle between the donor-recipient cartilage interface and cartilage surface normal near the graft boundary increased stresses when DRCR > 1, with the largest increase observed for an angle of 15°. A surface angle decreased stresses when DRCR < 1. Clinical Significance: This study highlights a potential mechanism to explain the high rates of failure of patellar OCAs. Additionally, the relationship between geometric features and stresses explored in this study led to a hypothetical scoring system that indicates which transplanted patellar grafts may have a higher risk of failure.

Osteochondral Allografts for Large Oval Defects of the Medial Femoral Condyle: A Comparison of Single Lateral Versus Medial Femoral Condyle Oval Grafts Versus 2 Overlapping Circular Grafts.

BACKGROUND: Studies have demonstrated the acceptability of using a contralateral nonorthotopic lateral femoral condyle (LFC) graft for a circular medial femoral condyle (MFC) osteochondral defect up to 20 to 25 mm in diameter. Larger oblong defects can now be managed using either overlapping circle grafts or a single oblong-shaped osteochondral allograft (OCA). PURPOSE: To determine if an oblong contralateral nonorthotopic LFC OCA can attain an acceptable surface contour match compared with an oblong ipsilateral MFC OCA or an overlapping circle technique for large oblong defects of the MFC. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 120 fresh-frozen human femoral condyles were matched by tibial width into 30 groups of 4 condyles (1 recipient MFC, 3 donor condyles). The recipient MFC was initially imaged using nano-computed tomography (nano-CT). A 17 × 36-mm oblong defect was created in the recipient MFC. Overall, 3 donor groups were formed: MFC oblong, LFC nonorthotopic oblong, LFC or MFC overlapping circles. After each transplant, the recipient condyle underwent nano-CT and was digitally reconstructed, which was superimposed on the initial nano-CT scan of the native recipient condyle. Dragonfly 3D software was used to determine the root mean square (RMS) of both the surface height deviation and the circumferential step-off height deviation between the native and donor cartilage surfaces for each graft. RESULTS: RMS surface height deviations were as follows: 0.59 mm for MFC oblong grafts, 0.58 mm for LFC oblong grafts, and 0.78 mm for overlapping circle grafts. The MFC and LFC oblong grafts had significantly less surface height deviation than the overlapping circle grafts (P = .004 and P = .002, respectively). RMS step-off height deviations were as follows: 0.68 mm for MFC oblong grafts, 0.70 mm for LFC oblong grafts, and 0.85 mm for overlapping circle grafts. The MFC and LFC oblong grafts had significantly less step-off height deviation than the overlapping circle grafts (P < .001 and P = .002, respectively). The majority of this difference was on the medial segment of the overlapping circle grafts. CONCLUSION: Oblong ipsilateral MFC OCAs and oblong contralateral nonorthotopic LFC OCAs produced a significantly better surface contour match to the native MFC than overlapping circle grafts for oblong defects 17 × 36 mm in size. CLINICAL RELEVANCE: Size-matched contralateral nonorthotopic LFC grafts are acceptable for MFC defects, which may allow for a quicker match, earlier patient care, and less wastage of valuable donor tissue.

Factors Associated With Humeral Avulsion of Glenohumeral Ligament Lesions in Patients With Anterior Shoulder Instability: An Analysis of the MOON Shoulder Instability Cohort.

Background: Humeral avulsion of the glenohumeral ligament (HAGL) lesions are an uncommon cause of anterior glenohumeral instability and may occur in isolation or combination with other pathologies. As HAGL lesions are difficult to detect via magnetic resonance imaging (MRI) and arthroscopy, they can remain unrecognized and result in continued glenohumeral instability. Purpose: To compare patients with anterior shoulder instability from a large multicenter cohort with and without a diagnosis of a HAGL lesion and identify preoperative physical examination findings, patient-reported outcomes, imaging findings, and surgical management trends associated with HAGL lesions. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Patients with anterior glenohumeral instability who underwent surgical management between 2012 and 2020 at 11 orthopaedic centers were enrolled. Patients with HAGL lesions identified intraoperatively were compared with patients without HAGL lesions. Preoperative characteristics, physical examinations, imaging findings, intraoperative findings, and surgical procedures were collected. The Student t test, Kruskal-Wallis H test, Fisher exact test, and chi-square test were used to compare groups. Results: A total of 21 HAGL lesions were identified in 915 (2.3%) patients; approximately one-third (28.6%) of all lesions were visualized intraoperatively but not identified on preoperative MRI. Baseline characteristics did not differ between study cohorts. Compared with non-HAGL patients, HAGL patients were less likely to have a Hill-Sachs lesion (54.7% vs 28.6%; P = .03) or an anterior labral tear (87.2% vs 66.7%; P = .01) on preoperative MRI and demonstrated increased external rotation when their affected arm was positioned at 90° of abduction (85° vs 90°; P = .03). Additionally, HAGL lesions were independently associated with an increased risk of undergoing an open stabilization surgery (odds ratio, 74.6 [95% CI, 25.2-221.1]; P < .001). Conclusion: Approximately one-third of HAGL lesions were missed on preoperative MRI. HAGL patients were less likely to exhibit preoperative imaging findings associated with anterior shoulder instability, such as Hill-Sachs lesions or anterior labral pathology. These patients underwent open procedures more frequently than patients without HAGL lesions.

A modified Delphi consensus statement on patellar instability: part II.

Aims: The aim of this study was to establish consensus statements on medial patellofemoral ligament (MPFL) reconstruction, anteromedialization tibial tubercle osteotomy, trochleoplasty, and rehabilitation and return to sporting activity in patients with patellar instability, using the modified Delphi process. Methods: This was the second part of a study dealing with these aspects of management in these patients. As in part I, a total of 60 surgeons from 11 countries contributed to the development of consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest. Consensus was defined as achieving between 80% and 89% agreement, strong consensus was defined as between 90% and 99% agreement, and 100% agreement was considered unanimous. Results: Of 41 questions and statements on patellar instability, none achieved unanimous consensus, 19 achieved strong consensus, 15 achieved consensus, and seven did not achieve consensus. Conclusion: Most statements reached some degree of consensus, without any achieving unanimous consensus. There was no consensus on the use of anchors in MPFL reconstruction, and the order of fixation of the graft (patella first versus femur first). There was also no consensus on the indications for trochleoplasty or its effect on the viability of the cartilage after elevation of the osteochondral flap. There was also no consensus on postoperative immobilization or weightbearing, or whether paediatric patients should avoid an early return to sport.

A modified Delphi consensus statement on patellar instability: part I.

Aims: The aim of this study was to establish consensus statements on the diagnosis, nonoperative management, and indications, if any, for medial patellofemoral complex (MPFC) repair in patients with patellar instability, using the modified Delphi approach. Methods: A total of 60 surgeons from 11 countries were invited to develop consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest within patellar instability. Consensus was defined as achieving between 80% and 89% agreement, strong consensus was defined as between 90% and 99% agreement, and 100% agreement was considered to be unanimous. Results: Of 27 questions and statements on patellar instability, three achieved unanimous consensus, 14 achieved strong consensus, five achieved consensus, and five did not achieve consensus. Conclusion: The statements that reached unanimous consensus were that an assessment of physeal status is critical for paediatric patients with patellar instability. There was also unanimous consensus on early mobilization and resistance training following nonoperative management once there is no apprehension. The statements that did not achieve consensus were on the importance of immobilization of the knee, the use of orthobiologics in nonoperative management, the indications for MPFC repair, and whether a vastus medialis oblique advancement should be performed.

Treatment of combined complete tears of the anterior cruciate and medial collateral ligaments.

PURPOSE: To develop an evidence-based algorithm for the treatment of combined complete tears of the anterior cruciate ligament (ACL) and medial collateral ligament (MCL). METHODS: We performed a systematic review using computerized keyword searches of Medline, Embase, CINAHL (Cumulative Index to Nursing and Allied Health Literature), ACP Journal Club, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews. Two reviewers independently performed searches and article reduction. Studies that reported stratified outcomes data after the treatment of combined complete tears of the ACL and MCL were included. Data on clinical measures of laxity, range of motion, and strength, as well as subjective outcome measures, were summarized. RESULTS: Five different treatment approaches were reported. Outcomes were better if the ACL was reconstructed and reconstruction was delayed to allow a return of knee range of motion. In many cases, this delay may allow the MCL to heal. MCL repair or reconstruction may be required if valgus instability remains after an appropriate rehabilitation period. CONCLUSIONS: ACL reconstruction should be performed in a subacute time frame once full motion has returned. Valgus instability should be assessed at that time and MCL repair or reconstruction performed in those patients with persistent valgus instability. LEVEL OF EVIDENCE: Level IV, systematic review of Level I to IV studies.

The Role of Mesenchymal Stromal Cells in the Management of Knee Chondral Defects.

➤: Mesenchymal stromal cells (MSCs) are a subset of progenitor cells that help to promote tissue healing and regeneration through the secretion of various cytokines and growth factors. Although technically pluripotent, MSCs in vivo rarely repair damaged tissue through direct differentiation and engraftment. ➤: Augmentation of traditional marrow stimulation techniques with MSCs has been theorized to improve repair tissue quality and defect fill. Clinical trials evaluating this technique are limited but have shown modest improvements compared with isolated marrow stimulation. ➤: Various scaffolds also have been utilized in combination with MSCs to treat focal chondral defects. Although the techniques described are heterogeneous, many have shown promising early clinical outcomes. ➤: Newer techniques involving 3-dimensional bioprinted scaffolds seeded with MSCs allow for the recreation of complex architecture, more closely resembling articular cartilage. These techniques are evolving and have not yet been studied in human clinical trials.

The Effect of Patellar Surface Morphology on Subchondral Bone Alignment When Matching Patellar Osteochondral Allografts to the Central Ridge of the Patella.

BACKGROUND: Cartilage transplants in the patellofemoral joint have demonstrated lower success rates than in the femoral condyles. This is likely related to the more complex morphology and biomechanics of the joint. While previous studies have evaluated cartilage surface matching and congruence, little work has been done to study the associated subchondral bone congruency in these grafts. PURPOSE: To determine if differences in patellar morphology play a role in the alignment of the donor patellar osteochondral allograft subchondral bone with the native patellar subchondral bone. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 20 (10 Wiberg I and 10 Wiberg II/III) fresh-frozen human patellae were designated as recipients and size-matched to both a Wiberg I and a Wiberg II/III patellar donor. A 16-mm osteochondral allograft transplant to the central ridge of the patella was performed in random order with each matched donor. Transplanted patellae underwent a nano-computed tomography (nano-CT) scan, were digitally reconstructed, and were superimposed on the initial nano-CT scan of the native recipient patella. MATLAB was used to determine the surface height deviation between the native and donor subchondral bone surfaces. DragonFly 3-dimensional imaging software was used to measure subchondral bone step-off heights at the native-donor interface. Differences between matched and unmatched grafts were compared using a 2-way analysis of variance and the Sidak post hoc test. RESULTS: Subchondral bone surface deviation did not differ between Wiberg matched and unmatched allografts. The step-off height was significantly greater in unmatched (1.38 ± 0.49 mm) compared with matched (1.14 ± 0.52 mm) plugs (P = .015). The lateral quadrant step-off differed between matched (0.89 ± 0.43 mm) and unmatched (1.60 ± 0.78 mm) grafts (P = .007). CONCLUSION: While unmatched Wiberg patellar osteochondral allograft implantation did not result in significantly different subchondral bone surface height deviations, there was a significant difference in the circumferential subchondral bone step-off height in the lateral quadrant. Further investigation using finite element analysis modeling will help determine the role of subchondral bone surface on shear and compression force distributions in these areas. CLINICAL RELEVANCE: Given that subchondral bone stiffness and morphology play a role in cartilage health, subchondral bone congruency may play a role in graft survival. Understanding how this congruency plays a role in cartilage force distribution will help surgeons improve the long-term success of osteochondral allograft transplants.

Factors Associated With Shoulder Activity Level at Time of Surgery and at 2-Year Follow-up in Patients Undergoing Shoulder Stabilization Surgery.

BACKGROUND: Patients undergoing shoulder stabilization surgery have been shown to have elevated activity levels. Factors associated with shoulder activity in this patient population at baseline and after surgery are unknown. HYPOTHESIS: Patient-specific variables are associated with shoulder activity level at baseline and at 2-year follow-up in a cohort of patients undergoing shoulder stabilization surgery. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Patients undergoing shoulder stabilization surgery were prospectively enrolled. As part of the data collection process, patients completed a previously validated Shoulder Activity Scale. A regression analysis was performed to assess the association of patient characteristics with baseline and 2-year follow-up shoulder activity levels. RESULTS: A total of 764 (n = 612 men, n = 152 women) out of 957 patients (80%) undergoing shoulder stabilization surgery with a median age of 25 years had baseline and 2-year follow-up data and were included in the current analysis. The baseline shoulder activity level was associated with race ( P < .0001) and preoperative duration of instability (P < .0001). At 2 years, 52% of the cohort had returned to the same or higher activity level after surgery. Predictors of higher shoulder activity level at 2-year follow-up included higher baseline activity level (P < .0001), male sex (P < .0001), younger age (P = .004), higher body mass index (BMI) (P = .03), more dislocations (P = .03), nonsmokers (P = .04), and race (P = .04). CONCLUSION: A longer duration of preoperative symptoms was associated with a lower baseline activity in this cohort. High baseline preoperative shoulder activity, younger age, male sex, higher BMI, number of dislocations, and nonsmoking status predicted higher shoulder activity 2 years after shoulder stabilization surgery. REGISTRATION: NCT02075775 (ClinicalTrials.gov identifier).

Comparing the Efficacy of Kneeling Stress Radiographs and Weighted Gravity Stress Radiographs to Assess Posterior Cruciate Ligament Insufficiency.

BACKGROUND: Kneeling posterior cruciate ligament (PCL) stress radiographs are commonly used to evaluate PCL laxity. Patients, however, report significant pain, and the method's reproducibility may be challenged due to its dependence on patient body weight distribution to produce posterior tibial displacement. Weighted gravity stress radiography may offer better reproducibility and comfort than the kneeling technique, but its efficacy has not been studied. HYPOTHESIS: Weighted gravity PCL stress radiographs will be more comfortable and produce similar measurements of side-to-side difference in posterior tibial displacement when compared with the kneeling technique. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 3. METHODS: A total of 40 patients with nonoperatively or >6 months postoperatively treated PCL injuries (isolated or multiligamentous) underwent bilateral stress radiographs. Weighted gravity and kneeling stress radiographs were acquired, in random order, for each patient, as well as side-to-side difference in posterior tibial displacement between each knee, patient-reported visual analog scale knee pain (100 mm), time to acquire the images, and patient preference for technique. Paired t tests were used to compare the side-to-side difference, pain score, and time to complete the radiographs. RESULTS: There was no difference between the 2 radiographic methods in the mean side-to-side difference (gravity: 6.45 ± 4.61 mm, kneeling: 6.82 ± 4.60 mm; P = .72), time required to acquire radiographs (kneeling: 307.3 ± 140.5 seconds, gravity: 318.7 ± 151.1 seconds; P = .073), or number of radiographs taken to obtain acceptable images (kneeling: 3.6 ± 1.6, gravity: 3.7 ± 1.7; P = .73). Patients reported significantly less knee pain during the weighted gravity views (kneeling: 31.8 ± 26.6, gravity: 4.0 ± 12.0; P < .0001). Of the patients, 88% preferred the weighted gravity method. CONCLUSION: Weighted gravity stress radiographs produce similar side-to-side differences in posterior tibial translation compared with the kneeling stress technique, but do not rely on patient weightbearing and provide significantly better patient comfort. Clinicians should therefore consider the use of weighted gravity stress radiographs in clinical practice to minimize the pain associated with stress radiography while allowing for accurate decision making.

Relationship between Anatomical Risk Factors, Articular Cartilage Lesions, and Patient Outcomes Following Medial Patellofemoral Ligament Reconstruction.

OBJECTIVE: The purpose of this study was (1) to determine which risk factors for patellar instability were associated with the presence of patellofemoral cartilage lesions and (2) to determine how cartilage lesion presence, size, and grade affect postoperative disease-specific quality of life. DESIGN: Preoperative, intraoperative, and postoperative demographic, anthropometric (body mass index, Beighton score, hip rotation), radiographic (crossover sign, trochlear bump), cartilage lesion morphology (presence, size, location, grade), and outcomes data (Banff Patella Instability Instrument 2.0 [BPII 2.0]) were prospectively collected from patients undergoing isolated medial patellofemoral ligament reconstruction. For all knees (n = 264), single and multivariable logistic regression was used to determine if any patellar instability risk factors affected the odds of having a cartilage lesion. In patients with unilateral symptoms (n = 121), single variable linear regression was used to determine if the presence, size, or ICRS (International Cartilage Regeneration & Joint Preservation Society) grade of cartilage lesions could predict the 12 or 24+ month postoperative BPII 2.0 score. RESULTS: A total of 84.5% of knees had patellofemoral cartilage lesions (88.3% involved the distal-medial patella). Trochlear dysplasia (high grade: odds ratio = 15.7, P < 0.001; low grade: odds ratio = 2.9, P = 0.015) was associated with the presence of a cartilage lesion. The presence, size, and grade of cartilage lesions were not associated with 12 or 24+ month postoperative BPII 2.0 scores. CONCLUSIONS: Trochlear dysplasia was a risk factor for the development of patellofemoral cartilage lesions in this patient population. Cartilage lesions most commonly involve the distal-medial patella. There was no significant relationship between patellofemoral cartilage lesion presence, size, or grade and postoperative BPII 2.0 scores in short-term follow-up.