Citations

Objective: To determine the optimal environmental conditions for chondrogenic differentiation of human adipose tissue–derived mesenchymal stromal/stem cells (AMSCs). In this investigation we specifically investigate the role of oxygen tension and 3-dimensional (3D) culture systems. Design: Both AMSCs and primary human chondrocytes were cultured for 21 days in chondrogenic media under normoxic (21% oxygen) or hypoxic (2% oxygen) conditions using 2 distinct 3D culture methods (high-density pellets and poly-ε-caprolactone [PCL] scaffolds). Histologic analysis of chondro-pellets and the expression of chondrocyte-related genes as measured by reverse transcriptase quantitative polymerase chain reaction were used to evaluate the efficiency of differentiation. Results: AMSCs are capable of expressing established cartilage markers including COL2A1, ACAN, and DCN when grown in chondrogenic differentiation media as determined by gene expression and histologic analysis of cartilage markers. Expression of several cartilage-related genes was enhanced by low oxygen tension, including ACAN and HAPLN1. The pellet culture environment also promoted the expression of hypoxia-inducible cartilage markers compared with cells grown on 3D scaffolds. Conclusions: Cell type–specific effects of low oxygen and 3D environments indicate that mesenchymal cell fate and differentiation potential is remarkably sensitive to oxygen. Genetic programming of AMSCs to a chondrocytic phenotype is effective under hypoxic conditions as evidenced by increased expression of cartilage-related biomarkers and biosynthesis of a glycosaminoglycan-positive matrix. Lower local oxygen levels within cartilage pellets may be a significant driver of chondrogenic differentiation.

Abstract Varus knee malalignment caused by medial compartment arthritis results in progressive asymmetric wear of the tibiofemoral joint. This wear can cause progressively painful gonarthrosis. Surgical methods to address varus knee malalignment include lateral closing‐wedge proximal tibial osteotomy, medial opening‐wedge osteotomy, and arthroplasty. Medial opening‐wedge proximal tibial osteotomy is an effective procedure for restoring proper coronal alignment and reducing knee pain. In this technical note, we present a reproducible technique for proximal tibial osteotomy. Technique Video video See video under supplementary data.

Background: Hip arthroscopy for young patients with femoroacetabular impingement (FAI) has been successful, but the efficacy of hip arthroscopy in older patients is not clearly defined. Purpose: To evaluate the clinical outcomes of patients 55 years and older who are undergoing hip arthroscopy and to compare outcomes with those of patients younger than 55 years. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 201 (63 male, 138 female) patients undergoing primary hip arthroscopy for FAI without radiographic arthritis (Tönnis grade <3) were isolated from a prospective database and stratified by age to <55-year and ≥55-year groups. Patients were evaluated preoperatively and 1 and 2 years postoperatively using the modified Harris Hip Score (mHHS) and Hip Outcome Score (HOS: functional scores, as well as Activities of Daily Living [ADL] and Sport subscales). A Wilcoxon signed rank sum test was used to evaluate the differences in outcome scores between the cohorts at each interval. Results: The <55-year group included 174 patients (mean age, 37 ± 12 years), and the ≥55-year group included 27 patients (mean age, 61 ± 5 years). The minimum follow-up time was 2 years in each group. Preoperative Tönnis grades and mHHS scores (59 vs 59; P = .75) were similar between groups. The ≥55-year cohort underwent labral debridement more frequently (78% vs 36%; P =.02) and were more likely to have full-thickness cartilage defects (22% vs 4%; P = .04). Despite this, the mHHS in both groups improved significantly from baseline, without significant differences at 1 year (86 [≥55 years] vs 81 [<55 years]; P = .53) or 2 years (73.88 [≥55 years] vs 79.54 [<55 years]; P = .06). However, at a minimum 2-year follow-up, patients <55 years had significant improvements over patients ≥55 years in the HOS subscales for ADL score (85.6 vs 75.2; P = .03), ADL rating (80.1 vs 70.0; P = .004), Sport score (70.2 vs 55.6; P = .04), and Sport rating (70.2 vs 58.0; P = .04). Conclusion: Although younger patients had superior HOS outcomes reported at 2 years compared with older patients after hip arthroscopy for FAI, both groups had significant improvement compared with their baseline. These data suggest that carefully selected patients 55 years and older without radiographic arthritis may benefit from hip arthroscopy.

Abstract Coronal limb malalignment is a significant contributor to asymmetric joint wear, gait abnormalities, and the development and progression of degenerative joint disease. Osteotomies about the knee were developed to realign the mechanical axis of the limb to unload the affected compartment. Valgus malalignment is less common than varus malalignment, but can contribute to a variety of clinical conditions, including lateral compartment cartilage defects and arthritis, lateral patellofemoral instability, and medial collateral ligament laxity. In this article, we describe our preferred operative technique for a lateral opening wedge varus‐producing distal femoral osteotomy to correct mild to moderate valgus malalignment. Technique Video video See video under supplementary data.

Purpose To (1) evaluate long‐term outcomes of osteochondral allograft (OCA) with regard to clinical outcome scores, reoperation and failure rates, and (2) examine if certain factors predispose patients to worse outcomes. Methods A comprehensive review was performed with specific inclusion criteria for studies with long‐term outcomes after OCA. Studies reported on patient clinical scores such as Hospital for Special Surgery score, Knee Society Score (knee and function score), and Lysholm score. Reoperation and failure rates were recorded for each study. Modified Coleman Methodology Scores assessed study methodological quality. Results Five studies with a total of 291 patients (55% male, 45% female) and average age of 34.8 years (range, 15 to 69 years) were included. Of all lesions, 67% were on the femoral condyles, 29% on the tibial plateau, and 4% were patellofemoral. All scores (Knee Society Function Score, Knee Society Knee Score, and Lysholm score) have significant mean improvement from preoperative to final follow‐up. The mean postoperative Hospital for Special Surgery score was 84.1. The mean failure rate was 25% at 12.3 years with a reoperation rate of 36%. A total of 72% of the failures were conversion to total (68%) or unicompartmental (4%) knee arthroplasty and 28% involved graft removal, graft fixation, and graft revision. Patellofemoral lesions (83%) had a significantly higher reoperation rate than lesions involving the tibial plateau or the femoral condyles (34%, P = .01). Conclusions Overall, OCA demonstrated significant improvements in clinical outcome scores and good durability with successful outcomes in 75% of the patients at 12.3 years after surgery. Patellofemoral lesions are associated with decreased clinical improvement and more frequent reoperations. The orthopaedic literature is limited by heterogeneity in surgical technique, lesion and patient characteristics, and reporting of nonstandardized outcome measures. Level of Evidence Level IV, systematic review of Level II and IV studies.

Background: Female soccer players have a well-known risk for anterior cruciate ligament (ACL) injury, but few studies have reported on second ACL injuries in this population. Purpose: To (1) report the rates of subsequent ACL injury (ipsilateral graft rupture or contralateral tear) in competitive female soccer players, (2) compare these rates with those of other female athletes of similar competitive level, (3) determine risk factors for second ACL injury, and (4) report clinical outcome scores in this population. Study Design: Cohort study; Level of evidence, 3. Methods: The medical records at a single institution were reviewed for female patients who were injured during a competitive athletic event and treated with primary ACL reconstruction (ACLR) between 1998 and 2013. Patients were followed for a mean of 68.8 months postoperatively (range, 24-115.2 months). Clinical outcome was obtained via Lysholm and International Knee Documentation Committee (IKDC) scores. Soccer players were matched 1:1 to non-soccer athletes for age, activity level, and graft type. Results: A total of 180 female ACLR patients with a mean ± SD age of 19.6 ± 6.9 years met the study inclusion and exclusion criteria (90 soccer players and 90 non-soccer players). Soccer players sustained more second ACL injuries, including both graft failures (11% vs 1%; P < .01) and contralateral ACL tears (17% vs 4%; P < .01), compared with non-soccer players. Of the 67 patients who returned to soccer after ACLR (mean age, 17.5 years; range, 13-27 years), significantly more had graft tears compared with those who did not return to soccer (15% vs 0%, respectively; P = .04); however, the difference in contralateral ACL tears (19% for returning players vs 9% for those who did not return; P = .34) was not significant. Relatively older age (odds ratio, 1.5 per year; P = .03) was a significant risk factor for ACL graft tear but not for contralateral ACL injury. Both groups had similar mean Lysholm (96 vs 95) and IKDC scores (95 vs 96) at final follow-up. Conclusion: Twenty-eight percent of all female soccer players and 34% of those players who returned to soccer had a second ACL tear. Soccer players had an increased rate of both graft tear and contralateral ACL injury compared with similar non-soccer athletes. Older age and return to soccer were significant risk factors for graft rupture.

Purpose (1) To determine the radiographic correction/healing rate, patient‐reported outcomes, reoperation rate, and complication rate after distal femoral osteotomy (DFO) for the valgus knee with lateral compartment pathology. (2) To summarize the reported results of medial closing wedge and lateral opening wedge DFO. Methods We conducted a systematic review of PubMed, MEDLINE, and CINAHL to identify studies reporting outcomes of DFOs for the valgus knee. Keywords included “distal femoral osteotomy,” “chondral,” “cartilage,” “valgus,” “joint restoration,” “joint preservation,” “arthritis,” and “gonarthrosis.” Two authors first reviewed the articles; our study exclusion criteria were then applied, and the articles were included on the basis relevance defined by the aforementioned criteria. The Methodological Index for Nonrandomized Studies scale judged the quality of the literature. Sixteen studies were relevant to the research questions out of 191 studies identified by the original search. Results Sixteen studies were identified reporting on 372 osteotomies with mean follow‐up of 45 to 180 months. All studies reported mean radiographic correction to a near neutral mechanical axis, with 3.2% nonunion and 3.8% delayed union rates. There was a 9% complication rate and a 34% reoperation rate, of which 15% were converted to arthroplasty. There were similar results reported for medial closing wedge and lateral opening wedge techniques, with a higher conversion to arthroplasty in the medial closing wedge that was confounded by longer mean follow‐up in this group (mean follow‐up 100 v 58 months). Conclusions DFOs for the valgus knee with lateral compartment disease provide improvements in patient‐reported knee health–related quality of life at midterm follow‐up but have high rates of reoperation. No evidence exists proving better results of either the lateral opening wedge or medial closing wedge techniques. Level of Evidence Level IV, systematic review of Level IV studies.

Purpose To determine whether the amount of pain relief after preoperative intra‐articular (IA) anesthetic injection predicts clinical and functional outcomes after hip arthroscopy, especially when controlling for the presence of chondral degeneration. Methods We identified patients who underwent IA injection and subsequent hip arthroscopy for labral pathology between 2007 and 2013 performed by a single surgeon. Inclusion criteria were ultrasound‐ or fluoroscopic‐guided IA anesthetic injection performed at our institution, prospectively documented pre‐ and postinjection numerical rating scale pain scores, and minimum 1‐year follow‐up postoperatively. Patients were divided into 2 groups, those who received >50% pain relief from preoperative IA anesthetic injection and those who received ≤50% relief. Preoperative radiographs were reviewed, and degree of osteoarthritis was determined using the Tonnis classification system. Outcomes were assessed with Modified Harris Hip Score and Hip Outcome Score (HOS). Univariate and multivariate models were performed to assess whether percent pain relief correlated with outcome. Results Of the 319 arthroscopic hip surgeries performed between 2007 and 2013, 115 (37%) patients were lost to follow‐up, 16 (5%) patients did not receive an IA injection, 16 (5%) patients had an injection containing gadolinium, and 40 (13%) patients completed injections at an outside institution. Five (2%) patients were excluded for a history of ipsilateral hip surgery, and 3 (1%) for a history of contralateral hip surgery, leaving 96 hips in 96 patients. There were 71 females (74%) and 25 males (26%) with a mean age of 37.6 ± 14.0 years. Tonnis was grade 0, 1, and 2 for 26 (27%), 55 (56%), and 16 (17%) patients, respectively. Fifty‐one (53%) of the injections contained a corticosteroid. The mean pain relief after IA injection was 73% ± 36% (range, 0% to 100%). Twenty‐six hips (26%) had ≤50% pain relief, whereas 70 (73%) had >50% pain relief, and the median time interval from injection to surgery was 3 (range, <1 to 20) months. Outcome scores were obtained at a mean 14.8 (range, 11 to 30) months after arthroscopic surgery. Postoperative mean Modified Harris Hip Score, HOS activities of daily living, and HOS‐Sport scores were 79.2 ± 17.3, 82.6 ± 17.3, and 67.4 ± 28.2, respectively. There was no statistical correlation between percent pain relief and outcome. There was no significant difference in outcome scores between those with ≤50% and >50% pain relief. Multivariate regression analysis showed no significant predictors of outcome, including age, gender, Tonnis grade, percent relief with IA injection, or type of surgery. Conclusions In this study of patients undergoing hip arthroscopy for labral pathology, our data indicate that the amount of pain relief from IA injection may be a poor predictor of short‐term outcome, even when adjusting for chondral degeneration. Although anesthetic injections can be an important diagnostic tool in select patients, a combination of the clinical history, physical examination, and imaging findings is fundamental. Level of Evidence Level IV, therapeutic case series.

Purpose To (1) report outcomes for patients who underwent revision meniscal repair and (2) define both clinical and surgical risk factors for recurrent failure. Methods The records of all patients who underwent revision meniscal repair between 1997 and 2012 were retrospectively reviewed. Surgical technique of primary and revision meniscus repair was detailed, and tears were characterized by type and location. Clinical examination and International Knee Documentation Committee (IKDC) and Tegner scores were used to determine outcomes after revision meniscus repair. Radiographs were reviewed and graded for degenerative changes. Risk factors for failure were analyzed. Results Thirty‐four patients (24 male/10 female) with an average age of 22 ± 6 years (range, 14 to 38) were included in this study. Twelve lateral menisci and 22 medial meniscal repairs were revised at mean 25 ± 20 months (range, 2 to 76) after primary repair for 11 simple, 9 bucket‐handle, and 14 complex tear patterns. Twenty‐one tears occurred in the red‐red zone and 13 in the red‐white zone. At 72 ± 56–month follow‐up (range, 2 to 17 years), 7 (21%) cases had documented failure of revision repairs and underwent subsequent partial meniscectomy. Mean Tegner score for all patients was 6.2 ± 1.5 (range, 3 to 9) and IKDC score was 84.8 ± 13.1 (range, 51.7 to 100) at final follow‐up. Affected side joint space on radiographs remained stable from a baseline of 4.26 ± 0.88 mm to a final of 4.01 ± 0.84 mm. Multivariable regression identified younger patient age as an independent risk factor for failed revision meniscal repair ( P = .01). Conclusions In this study of select revision meniscus repairs, 79% of patients were pain free, without any mechanical symptoms or additional surgeries at a mean of 6 years after revision repair. Younger patients may be at higher risk of failure of the revision meniscus repair. Level of Evidence Level IV, therapeutic case series.

Purpose To compare clinical and functional outcomes of surgically treated medial and lateral knee dislocations. Methods A retrospective review of the medical records of patients who presented with knee dislocations was conducted. We identified patients who underwent surgical treatment of KDIII‐M (anterior cruciate ligament/posterior cruciate ligament/medial collateral ligament) or KDIII‐L (anterior cruciate ligament/posterior cruciate ligament/lateral collateral ligament) knee dislocation as documented by the Schenck classification. Minimum 2‐year follow‐up with Lysholm and International Knee Documentation Committee (IKDC) outcome scores was required for inclusion. Postoperative range of motion, ligamentous examination, and conversion to total knee arthroplasty were also collected. Data were analyzed using univariate and multivariate statistical models with P < .05 considered significant. Results A total of 56 patients met the inclusion criteria, 24 with the KDIII‐M injury pattern (43%) and 32 with the KDIII‐L injury pattern (57%), with a mean age of 34 years (range, 16 to 62 years) and a mean follow‐up of 6.5 years (range, 2 to 20 years). Patients undergoing medial repairs had worse outcomes for both the Lysholm score ( P = .008) and IKDC score ( P = .003). In addition, female sex was linked to worse outcomes (Lysholm score, 58.8 ± 21.5 v 77.8 ± 21.1, P < .01; IKDC score, 54.9 ± 23.7 v 75.2 ± 20.2, P < .01). No differences in outcome were found between patients with and patients without peroneal nerve injury (Lysholm score, P = .81; IKDC score, P = .77). No difference in laxity testing was found between the 2 groups. Conclusions In patients undergoing multiligament knee reconstruction, our data suggest that those who undergo medial repair for knee dislocations are not as likely to achieve positive results as those who undergo reconstruction or lateral reconstruction/repair, regardless of the status of the peroneal nerve. In addition, medial reconstruction had comparable outcomes to those in patients treated with lateral reconstruction/repair. Lastly, female patients showed less favorable clinical outcomes than male patients. Level of Evidence Level III, retrospective comparative study.