Aaron J. Krych

A Meta-analysis of Patellar Tendon Autograft Versus Patellar Tendon Allograft in Anterior Cruciate Ligament Reconstruction

PURPOSE Studies have suggested good long-term success rates with bone-patellar tendon-bone (BPTB) autograft and BPTB allograft in anterior cruciate ligament (ACL) reconstruction, but the numbers reported in available prospective studies may be underpowered to elucidate significant differences between the two groups. Here, we present a meta-analysis to compare the results of BPTB autograft and BPTB allograft in primary ACL reconstruction. METHODS A systematic review of prospective trials using BPTB autograft and BPTB allograft tissue for ACL reconstruction with a minimum 2-year follow-up was performed. Summary odds ratios (ORs), confidence intervals, and P values were calculated. RESULTS Of 548 studies, 6 fulfilled our inclusion criteria, with 256 patients in the autograft and 278 patients in the allograft group. Allograft patients were more likely to rupture their graft than autograft patients (OR, 5.03; P = .01) and more likely to have a hop test less than 90% of the nonoperative side (OR, 5.66; P < .01). When irradiated and chemically processed grafts were excluded from analysis, no significant differences were found between allograft and autograft patients with respect to graft rupture, rate of reoperation, normal/near normal IKDC scores, Lachman exam, pivot shift exam, patellar crepitus, hop test, or return to sport. CONCLUSIONS In this meta-analysis, ACL reconstruction with BPTB autograft was favored over BPTB allograft for graft rupture and hop test parameters. However, when irradiated and chemically processed grafts were excluded, results were not significantly different between the two graft types. LEVEL OF EVIDENCE Level III, systematic review of prospective nonrandomized cohort studies.

Arthroscopic labral repair versus selective labral debridement in female patients with femoroacetabular impingement: a prospective randomized study.

PURPOSE The purpose of this prospective randomized study was to compare the outcomes of arthroscopic labral repair and selective labral debridement in female patients undergoing arthroscopy for the treatment of pincer-type or combined pincer- and cam-type femoroacetabular impingement. METHODS Between June 2007 and June 2009, 36 female patients undergoing arthroscopic hip treatment for pincer- or combined-type femoroacetabular impingement were randomized to 2 treatment groups at the time of surgery: labral repair or labral debridement. The repair group comprised 18 patients with a mean age of 38; the debridement group comprised 18 patients with a mean age of 39. All patients underwent the same rehabilitation protocol postoperatively. At a minimum of 1 year, all patients were assessed using a validated Hip Outcome Score (HOS) to determine hip function, and also completed a simple subjective outcome measure. RESULTS All 36 patients were available for follow-up at an average time of 32 months (range, 12 to 48). In both groups, HOSs for activities of daily living (ADL) and sports improved significantly from before surgery to the final follow-up (P < .05). The postoperative ADL HOS was significantly better in the repair group (91.2; range, 73 to 100) compared with the debridement group (80.9; range, 42.6 to 100; P < .05). Similarly, the postoperative sports HOS was significantly greater in the repair group (88.7; range, 28.6 to 100) than in the debridement group (76.3; range, 28.6 to 100; P < .05). Additionally, patient subjective outcome was significantly better in the labral repair group (P = .046). CONCLUSIONS Arthroscopic treatment of femoroacetabular impingement with labral repair in female patients resulted in superior improvement in hip functional outcomes compared with labral debridement. In addition, a greater number of patients in the repair group subjectively rated their hip function as normal or nearly normal after surgery compared with the labral debridement group. LEVEL OF EVIDENCE Level I, prospective randomized study.

Activity levels are higher after osteochondral autograft transfer mosaicplasty than after microfracture for articular cartilage defects of the knee: a retrospective comparative study.

BACKGROUND There is limited information regarding direct comparisons of the outcome of osteochondral autograft transfer (OAT) mosaicplasty and microfracture for the treatment of isolated articular cartilage defects of the knee. The purpose of this retrospective comparative study was to compare the general health outcomes, knee function, and Marx Activity Rating Scale scores for patients treated with OAT or microfracture for symptomatic chondral defects of the femoral condyles or trochlea. We hypothesized that the patients in the two treatment groups would have similar clinical outcomes at intermediate-term follow-up. METHODS Ninety-six patients with full-thickness cartilage defects of the femoral condyles or trochlea were treated with either OAT mosaicplasty (n = 48) or microfracture (n = 48). The average age of the patients (thirty-two male and sixteen female in each group) at the time of surgery was 29.7 years in the OAT group and 32.5 years in the microfracture group. Patients were prospectively evaluated at baseline and at one, two, three, and five years postoperatively with use of validated clinical outcome measures including the Short Form-36 (SF-36) physical component, International Knee Documentation Committee (IKDC), Knee Outcome Survey activities of daily living, and Marx Activity Rating Scale instruments. Comparisons between outcomes before and after treatment or between outcomes after microfracture and mosaicplasty were made with use of two-tailed tests. RESULTS At the time of the latest follow-up, both groups demonstrated significant increases in SF-36 physical component, Knee Outcome Survey activities of daily living, and IKDC scores compared with baseline. These scores did not differ significantly between the two groups at any of the follow-up time points. However, the OAT group demonstrated a significantly greater improvement in the Marx Activity Rating Scale scores from baseline to the two-year (p = 0.001), three-year (p = 0.03), and five-year (p = 0.02) time points compared with the microfracture group. CONCLUSIONS In the present retrospective comparative study, the hypothesis that patients treated with microfracture or OAT mosaicplasty for symptomatic articular cartilage defects of the femoral condyles or trochlea would have similar clinical outcomes at intermediate-term follow-up was affirmed for general health outcome and for knee function. However, patients treated with OAT mosaicplasty maintained a superior level of athletic activity compared with those treated with microfracture.

Return to Athletic Activity After Osteochondral Allograft Transplantation in the Knee

Background: Fresh-stored osteochondral allografts have been used successfully to resurface large chondral and osteochondral defects of the knee. However, there are limited data available for the return to athletic activity. Purpose: To review the rate of return to athletic activity after osteochondral allograft transplantation in the knee and to identify any potential risk factors for not returning to sport. Study Design: Case series; Level of evidence, 4. Methods: Forty-three athletes were treated with fresh-stored osteochondral allograft transplantation for symptomatic large chondral or osteochondral defects of the knee from 2000 to 2010. The average age of the athletes (30 men, 13 women) was 32.9 years (range, 18-49 years). Patients were prospectively evaluated by International Knee Documentation Committee (IKDC), activities of daily living scale of the Knee Injury and Osteoarthritis Outcome Score (KOOS), Marx Activity Rating Scale, and Cincinnati Sports Activity Scale scores. A multivariable regression analysis was performed to identify potential risk factors for failure to return to sport at the preinjury level. Results: At an average 2.5-year follow-up, limited return to sport was possible in 38 of 43 athletes (88%), with full return to the preinjury level achieved in 34 of 43 athletes (79%). In these 34 athletes, time to return to sport was 9.6 ± 3.0 months. Age ≥25 years (P = .04) and preoperative duration of symptoms greater than 12 months (odds ratio, 37; P = .003) negatively affected the ability to return to sport. In the athletes who returned to their previous level of competition, IKDC (P < .001), KOOS (P = .02), and Marx Activity Rating Scale (P < .001) scores were all significantly greater than in those athletes who did not return to sport. Conclusion: Osteochondral allograft transplantation in an athletic population for chondral and osteochondral defects in the knee allows for a high rate of return to sport. Risk factors for not returning to sport included age ≥25 years and preoperative duration of symptoms ≥12 months.

Medial Patellofemoral Ligament Repair for Recurrent Patellar Dislocation

Background The medial patellofemoral ligament (MPFL) is the primary restraint to extreme lateral displacement and is typically disrupted with an acute lateral patellar dislocation. Patients who fail a comprehensive nonoperative program and experience recurrent lateral patellar instability episodes are candidates for surgical treatment. Current surgical procedures include a variety of proximal realignment techniques, including repair or reconstruction of the MPFL along with distal realignment of the tibial tubercle when indicated. Purpose The objective of this study was to review the clinical, functional, and radiographic outcomes of isolated MPFL repair for recurrent lateral patellar dislocation. Study Design Case series; Level of evidence, 4. Methods The records of all patients undergoing MPFL repair for recurrent patellar dislocation at the Mayo Clinic from 2001 to 2006 were retrospectively reviewed. Twenty-seven patients (29 knees) with an average age of 19 years (range, 11-32 years) were included in this study. Clinical, functional, and radiographic outcomes were assessed at an average of 4 years after surgery (range, 2-7 years), using recurrent instability as the primary end point. Results The success rate of MPFL repair for preventing recurrent dislocations was 72% (21 of 29 knees). Eight patients (28%) experienced a recurrent lateral patellar dislocation. Five of these patients required a reoperation, including two MPFL reconstructions, 1 tibial tubercle osteotomy with MPFL reconstruction, 1 tibial tubercle osteotomy with revision MPFL repair, and 1 revision MPFL repair. At final follow-up, the mean Lysholm and Kujala scores were 86 (range, 42-100) and 92 (range, 57-105), respectively. Postoperative radiographs revealed a mean patellofemoral congruence angle improvement of 27° (range, 5°-44°). The only statistically significant risk factor for failure was nonanatomical MPFL repair at the medial femoral condyle (P = .004). Conclusion Isolated repair of the MPFL for recurrent patellar instability is associated with a relatively high failure rate, but remains a viable surgical option if surgical technique principles are followed. The clinical success of this operation depends on restoration of the anatomical origin of the MPFL and careful patient selection.

Total hip arthroplasty with shortening subtrochanteric osteotomy in Crowe type-IV developmental dysplasia.

BACKGROUND When surgeons perform total hip arthroplasty for hips with a high dislocation related to developmental dysplasia of the hip, obtaining long-term stable implant fixation and optimizing patient function remain challenges. The purpose of this paper was to evaluate the results of cementless arthroplasty with a simultaneous subtrochanteric shortening osteotomy in a group of patients with Crowe type-IV developmental dysplasia of the hip. METHODS In a retrospective study, we evaluated the results and complications of twenty-eight consecutive primary cementless total hip arthroplasties in twenty-four patients (twenty women and four men), all of whom had Crowe type-IV developmental dysplasia of the hip. The arthroplasty was performed in combination with a subtrochanteric shortening osteotomy and with placement of the acetabular component at the level of the anatomic hip center. The patients were evaluated at a mean of 4.8 years postoperatively. RESULTS The mean Harris hip score increased from 43 points preoperatively to 89 points at the time of final follow-up (p < 0.01). Twelve (43%) of the twenty-eight hips had an early or late complication or a reoperation. Two (7%) of the twenty-eight subtrochanteric osteotomies were followed by nonunion. There was one instance of isolated loosening of the femoral stem. One acetabular component loosened, and one acetabular liner disengaged. Four hips dislocated postoperatively. All remaining components were well-fixed at the time of the last radiographic follow-up. No sciatic neurapraxic injuries were identified. CONCLUSIONS Cementless total hip arthroplasty combined with a subtrochanteric femoral shortening osteotomy in patients with a high hip dislocation secondary to developmental dysplasia was associated with high rates of successful fixation of the implants and healing of the osteotomy site and a mean postoperative Harris hip score of 89 points. The complication rate, however, was substantially higher than that associated with primary total hip arthroplasty in patients with degenerative arthritis.

CT and MRI Measurements of Tibial Tubercle–Trochlear Groove Distances Are Not Equivalent in Patients With Patellar Instability

Background: Tibial tubercle–trochlear groove distance (TT-TG) is a commonly used measurement for surgical decision making in patients with patellofemoral malalignment and instability. This measurement has historically been performed utilizing axial computed tomography (CT). More recently, magnetic resonance imaging (MRI) has been proposed as an equivalent method, but this has not yet been fully validated. Purpose: To determine the reliability of TT-TG distance measurements on both MRI and CT and to determine whether the measurements are interchangeable with one another. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: All patients with patellar instability who underwent both CT and MRI of the knee from 2003 to 2011 were included (n = 59 knees in 54 patients). Two fellowship-trained musculoskeletal radiologists measured the TT-TG distances for each patient by CT and MRI in a randomized, blinded fashion. Interobserver reliability was calculated between radiologists for both imaging modalities, and intermethod reliability was calculated between the 2 imaging modalities. The results are reported using intraclass correlation coefficients (ICCs) and Bland-Altman analysis. Results: The 59 knees had a mean TT-TG distance of 16.9 mm (range, 8.3-25.8 mm) by CT and 14.7 mm (range, 1.5-25.1 mm) by MRI. Interobserver reliability between the radiologists was considered excellent for both CT and MRI (ICC = 0.777 and 0.843, respectively). When comparing CT to MRI, the ICC was considered only fair for each of the raters (0.532 and 0.539). Eleven patients (19%) had a TT-TG distance of ≥20 mm on CT preoperatively and underwent distal realignment by tibial tubercle osteotomy. In this surgical subgroup, the mean TT-TG distance was 22.5 mm (range, 19.8-25.8 mm) by CT and only 18.7 mm (range, 14.4-22.8 mm) by MRI for a mean difference of 3.80 mm (P < .001). Conclusion: The TT-TG distance can be measured with excellent interrater reliability on both MRI and CT; however, the values derived from these 2 tests may not be interchangeable. This observation should be taken into consideration when MRI is used for surgical planning because MRI may underestimate the TT-TG distance when compared with CT.

Incidence of Anterior Cruciate Ligament Tears and Reconstruction A 21-Year Population-Based Study

Background: The incidence of isolated anterior cruciate ligament (ACL) tears in the general population is not well defined. Purpose/Hypothesis: The purpose of this study was to define the population-based incidence of ACL tears, describe trends in ACL injuries over time, and evaluate changes in the rate of surgical management. The hypothesis was that the incidence of ACL injury and the rate of subsequent ACL reconstruction increase over time. Study Design: Cohort study; Level of evidence, 3. Methods: The study population included 1841 individuals who were diagnosed with new-onset, isolated ACL tears (without concomitant ligament injury that required surgery) between January 1, 1990, and December 31, 2010. The complete medical records were reviewed to confirm diagnosis and to extract injury and treatment details. Age- and sex-specific incidence rates were calculated and adjusted to the 2010 US population. Poisson regression analyses were performed to examine incidence trends by age, sex, and calendar period. Results: The overall age- and sex-adjusted annual incidence of ACL tears was 68.6 per 100,000 person-years. Incidence was significantly higher in male patients than in females (81.7 vs 55.3 per 100,000, P < .001). The incidence of isolated ACL tears decreased significantly over time in males (P < .001) but remained relatively stable in females. Age-specific patterns differed in male and female patients, with a peak in incidence (241.0 per 100,000) between 19 and 25 years in males and a peak in incidence (227.6 per 100,000) between 14 and 18 years in females. The rate of ACL reconstruction increased significantly over time in all age groups (P < .001). Conclusion: With an annual incidence of 68.6 per 100,000 person-years, isolated ACL tears remain a common orthopaedic injury. Differences in age-specific incidence trends in male and female patients may potentially reflect differences in sports participation patterns through the high school and college years. The significant increase in the rate of ACL reconstruction over time may reflect changing surgical indications or an increasing desire among patients to return to high levels of activity after ACL injury.

High-Resolution Molecular Validation of Self-Renewal and Spontaneous Differentiation in Clinical-Grade Adipose-Tissue Derived Human Mesenchymal Stem Cells

Improving the effectiveness of adipose‐tissue derived human mesenchymal stromal/stem cells (AMSCs) for skeletal therapies requires a detailed characterization of mechanisms supporting cell proliferation and multi‐potency. We investigated the molecular phenotype of AMSCs that were either actively proliferating in platelet lysate or in a basal non‐proliferative state. Flow cytometry combined with high‐throughput RNA sequencing (RNASeq) and RT‐qPCR analyses validate that AMSCs express classic mesenchymal cell surface markers (e.g., CD44, CD73/NT5E, CD90/THY1, and CD105/ENG). Expression of CD90 is selectively elevated at confluence. Self‐renewing AMSCs express a standard cell cycle program that successively mediates DNA replication, chromatin packaging, cyto‐architectural enlargement, and mitotic division. Confluent AMSCs preferentially express genes involved in extracellular matrix (ECM) formation and cellular communication. For example, cell cycle‐related biomarkers (e.g., cyclins E2 and B2, transcription factor E2F1) and histone‐related genes (e.g., H4, HINFP, NPAT) are elevated in proliferating AMSCs, while ECM genes are strongly upregulated (>10‐fold) in quiescent AMSCs. AMSCs also express pluripotency genes (e.g., POU5F1, NANOG, KLF4) and early mesenchymal markers (e.g., NES, ACTA2) consistent with their multipotent phenotype. Strikingly, AMSCs modulate expression of WNT signaling components and switch production of WNT ligands (from WNT5A/WNT5B/WNT7B to WNT2/WNT2B), while upregulating WNT‐related genes (WISP2, SFRP2, and SFRP4). Furthermore, post‐proliferative AMSCs spontaneously express fibroblastic, osteogenic, chondrogenic, and adipogenic biomarkers when maintained in confluent cultures. Our findings validate the biological properties of self‐renewing and multi‐potent AMSCs by providing high‐resolution quality control data that support their clinical versatility. J. Cell. Biochem. 115: 1816–1828, 2014.

Surgical Repair of Meniscal Tears with Concomitant Anterior Cruciate Ligament Reconstruction in Patients 18 Years and Younger

Background There are sparse data available regarding outcome of meniscal repair performed at the time of ACL reconstruction in the pediatric and adolescent population. Purpose To review the results of meniscal repair performed at the time of ACL reconstruction in pediatric and adolescent patients. Study Design Case series; Level of evidence, 4. Methods The records of all patients age 18 years or younger who underwent meniscal repair at the time of ACL reconstruction between 1990 and 2005 were reviewed. Ninety-nine patients (56 female, 43 male) with an average age of 16 years (range, 13-18) were included. Average injury to surgery interval was 107 days (range, 2-1109). Clinical outcomes were assessed at a mean of 8 years postoperatively (range, 2-19). A multivariate model was used to compare this cohort with a previously published cohort of patients with isolated meniscal tears. Results The clinical success rate of meniscal repair was 84% for simple tears, 59% for displaced bucket-handle tears, and 57% for complex tears (74% overall). Twenty-six menisci (26% overall) failed repair and 25 patients underwent repeat arthroscopic surgery (19 partial meniscectomies, 6 re-repairs). The average Tegner and International Knee Documentation Committee scores were 6.2 (range, 2-10) and 90.3 (range, 52-100), respectively. Risk factors for failure included complex and bucket-handle tear (P = .01), medial meniscal tears (P = .03), and skeletal immaturity (P = .01). Compared with isolated meniscal repairs in a similar pediatric and adolescent population, complex tears repaired in combination with ACL reconstruction did significantly better (57% vs 13%; P = .004). Conclusion Clinically successful repair of meniscal tears treated at the time of ACL reconstruction in patients 18 years or younger depends on tear type, with complex and bucket-handle tears being negative prognostic factors. Complex tears have a higher rate of clinical success when repaired at the time of ACL reconstruction versus when repaired in isolation.