Alexander H. King

Is Subchondral Acetabular Edema or Cystic Change on MRI a Contraindication for Hip Arthroscopy in Patients With Femoroacetabular Impingement

Background: The outcome for arthroscopic treatment of femoroacetabular impingement (FAI) can worsen with increasing arthritis. However, there remains a subset of hips with relatively maintained joint space but with acetabular subchondral edema and cystic change with unknown outcome on magnetic resonance imaging (MRI). Purpose: (1) To correlate MRI findings of subchondral acetabular edema/cystic change with arthroscopy grading of articular cartilage and (2) to determine whether postoperative outcome was worse for patients with subchondral edema/cystic change compared with a matched control group. Study Design: Cohort study; Level of evidence, 3. Methods: The records of all patients who underwent arthroscopic hip surgery for FAI at a single institution between 2007 and 2013 were reviewed for subchondral edema/cyst on preoperative MRI. Lesions were characterized by grade using an established classification system and were correlated with arthroscopic articular cartilage changes. A matched cohort of patients without evidence of subchondral edema or cyst was identified. Minimum 2-year outcomes were compared using prospectively collected Hip Outcome Score (HOS) activities of daily living and sport subscales as well as the modified Harris Hip Score (mHHS). Results: Overall, 104 patients were included. Thirty-six patients (18 men, 18 women) with a mean age of 41 years (range, 19-67 years) had subchondral edema, with or without the presence of cystic acetabular changes, at minimum 2-year follow-up (range, 24-60 months). Two patients who underwent total hip replacement were excluded in the outcome score comparison. Thirty-one of 34 patients (91%) had a grade 4 full-thickness cartilage lesion at the time of diagnostic arthroscopy. The mean mHHS was inferior for all patients with subchondral edema/cystic change (79.9 ± 18.7 vs 86.6 ± 12.5; P = .03), and the HOS was also lower (69.1 ± 27.0 vs 79.5 ± 21.4; P = .02). The overall success rate was 67% for all patients with subchondral edema/cystic change compared with 85% in the control group (P = .04). Conclusion: The presence of a subchondral edema with an acetabular cyst on MRI is indicative of a full-thickness cartilage lesion at the time of arthroscopy. These patients have inferior outcomes for arthroscopic treatment of FAI compared with patients with similar age and activity level without MRI subchondral cystic changes.

MRI injury patterns in surgically confirmed and reconstructed posterolateral corner knee injuries.

PurposeThe posterolateral corner (PLC) of the knee is anatomically complex with similarly complex MR imaging findings in acutely injured knees. The purpose of this study was to define the MRI pattern of injury in cases of PLC disruption requiring surgery because of clinical instability.MethodsThe knee MRIs of 22 patients who underwent surgical repair and/or reconstruction of PLC injury were retrospectively reviewed. The fibular collateral ligament (FCL), popliteus tendon (PT), biceps femoris (BF), popliteofibular ligament (PFL), arcuate ligament (AL), and fabellofibular ligament (FFL) were evaluated and graded as follows: complete tear, high-grade partial tear, low-grade partial tear, and normal.ResultsIn the 22 cases of PLC injury that necessitated surgery, a constellation of findings involving the larger structures of the PLC was identified. Of the FCL, PT, and BF (considered larger structures), at least two were abnormal in all 22 injury cases. Of the PFL, AL, and FFL (considered smaller structures), the PFL appeared abnormal in 19 cases, yet neither the AL nor FFL were confidently characterized in the injury group.ConclusionThe larger structures of the PLC are easily evaluated using standard MRI techniques. This study identified a predictable pattern of imaging findings involving these more easily assessed structures in those patients who were felt to be clinically unstable and underwent surgical reconstruction, as at least two were abnormal in all 22 cases. The smaller structures of the PLC are difficult to assess with MRI; however, direct visualization of their involvement on MRI is not necessary to report a clinically unstable PLC injury. Emphasis of this simplified but critical analysis of the FCL, BF and PT on MRI scans reviewed by radiologists and orthopaedic surgeons may help to prevent delayed diagnosis of unstable PLC injuries.Level of evidenceIII.

Internal Fixation of Unstable Osteochondritis Dissecans in the Skeletally Mature Knee with Metal Screws

Purpose Several bioabsorbable and metal options are available for internal fixation of an unstable osteochondritis dissecans (OCD) lesion, but currently there are little data on outcomes with metal headless compression screws in the adult knee. The purpose of this study was to determine (1) the radiographic healing rates, (2) midterm clinical outcomes, and (3) comparison between healed and unhealed OCD fragments after use of headless metal compression screws for the treatment of unstable OCD lesions in the knees of skeletally mature patients. Methods Retrospective chart review for all skeletally mature patients who presented with unstable femoral condyle OCD lesions of the knee was conducted. All patients underwent open or arthroscopic reduction and internal fixation using headless metal compression screws. Preoperative and postoperative radiographs were reviewed with healing defined as radiographic evidence of union of the OCD progeny fragment with the condyle. Clinical outcome data were collected retrospectively using 3 validated outcome scores: International Knee Documentation Committee (IKDC), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Marx. Results Twenty-two knees in 22 patients with a mean age of 21 years (range= 14-37 years) were followed for an average of 8.7 years (range = 2-22 years). Metal, headless, cannulated compression screws were used in all 22 cases. At a mean of 31 months postoperatively (range = 2-262), fragment union was observed in 18 knees (82%). The remaining 4 knees (18%) required loose fragment excision and hardware removal at a mean of 9 months (range = 2-16 months) postoperatively. Mean postoperative Marx score was 7 (range = 0-16), the mean postoperative IKDC score was 85 (range = 62-100), and mean KOOS scores included KOOS Pain (93; range = 69-100), KOOS Symptoms (86; range = 71-100), KOOS ADL (98; range = 90-100), KOOS Sports (82; range = 50-100), and KOOS QOL (76; range = 50-100). Conclusion Headless metal compression screws provide a satisfactory union rate for treatment of unstable OCD lesions of the femoral condyles in skeletally mature patients. Patients achieving union have good knee function, maintain satisfactory activity levels, and have superior knee outcomes compared with those that failed to heal after fixation at mid to long-term follow-up.

The Effect of Cartilage Injury After Arthroscopic Stabilization for Shoulder Instability

This study was undertaken to (1) determine the incidence of articular cartilage injuries in patients with instability of the glenohumeral joint, (2) determine whether recurrent dislocations increased the risk of articular damage, and (3) correlate these injuries with postoperative clinical outcomes. A cohort was identified of consecutive patients who underwent diagnostic magnetic resonance imaging and shoulder arthroscopy for glenohumeral instability with documented dislocation or subluxation between 1997 and 2006 at a single institution. Patients with moderate or severe osteoarthritis were excluded. Arthroscopic findings were recorded, including lesion location and Outerbridge grade. The American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) was used to assess outcome in 61 patients who were available for follow-up. Outcomes were compared between shoulders with and without articular lesions. A total of 87 shoulders (83 patients) met the inclusion criteria, with 69 (83%) men and 14 (17%) women. Mean age was 26.1 years (range, 18-64 years), and mean follow-up was 36 months (range, 33-39 months). Cartilage injuries were found in 56 shoulders (64%). Previously documented shoulder dislocation requiring closed reduction (P=.046) and the number of discrete dislocations (P=.032) were significant for glenoid injury. A greater number of dislocations was associated with higher-grade lesions of the glenohumeral joint (P<.001). Overall, mean ASES score was 89.6 (range, 37-100). In patients with an articular cartilage lesion, mean ASES score was 90.4 (range, 58-100) compared with 88.1 (range, 37-100) in those without this injury (P=.75). Although clinical outcomes were not significantly affected, further investigation is warranted to establish a relationship between these injuries and longer-term outcomes.

Treatment of Patellofemoral Cartilage Lesions in the Young, Active Patient

Articular cartilage lesions of the patella and trochlea are commonly encountered in the young and active patient. These defects can be classified as chondral or osteochondral, and then further described according to size, location, and etiology. Early surgical intervention is often indicated for traumatic injuries resulting in osteochondral damage, including acute patellofemoral dislocation. For chronic lesions, initial treatment involves exhaustive nonoperative measures, and surgery is reserved for patients with persistent symptoms. A thorough history, physical examination, and imaging are essential to select the best surgical option. Cartilage restoration procedures are combined with optimization of background factors such as patellofemoral alignment and congruity to achieve success. Cell-based therapies have evolved into a reliable strategy for management of these lesions.

All-Inside Posterior Cruciate Ligament Reconstruction: GraftLink Technique

Posterior cruciate ligament (PCL) injuries account for nearly 20% of knee ligament injuries. PCL injuries can occur in isolation or, more commonly, in the setting of multiligamentous knee injuries. Isolated PCL disruptions are commonly treated nonoperatively; however, symptomatic grade III injuries, as well as PCL injuries found in multiligamentous injuries, are frequently treated surgically. Several reconstructive techniques exist for the treatment of PCL deficiency without a clear optimal approach. We describe our preferred operative technique to reconstruct the PCL using an all-inside arthroscopic approach with a quadrupled tibialis anterior or peroneus longus allograft with both tibial and femoral suspensory fixation.

Open Anatomic Reconstruction of the Medial Collateral Ligament and Posteromedial Corner.

Injuries to the medial collateral ligament (MCL) and posteromedial corner can occur in isolation or in the setting of multiligamentous knee injuries. Reconstruction of the MCL and posteromedial corner is indicated in the setting of a multiligamentous knee injury. Isolated cases failing nonoperative treatment may also undergo surgical treatment. Our preferred technique for anatomic medial-sided knee reconstruction is an open anatomic MCL reconstruction using an Achilles tendon allograft along with direct repair of all associated medial and posteromedial structures.

Increased Risk of Second Anterior Cruciate Ligament Injury for Female Soccer Players

Objectives: Female athletes are an at-risk population for anterior cruciate ligament (ACL) injury, with rates of injury significantly higher than the general population. Few studies have reported on a second ACL injury for female athletes. The purpose of this study was to (1) report the rate of subsequent ACL injury (ACL graft rupture or contralateral ACL tear) in competitive female soccer players, (2) compare these rates to those of other female athletes of similar competitive level, and (3) determine risk factors for second ACL injury in this athletic population. Methods: The medical record at our institution was reviewed for patients treated with primary ACL reconstruction between 1998 and 2013. Female patients injured during a competitive athletic event were included for further review, and followed for an average of 7.1 years postoperatively (range 1.0 - 17.7 years). Chi-square analysis was used to compare rate of graft rupture and contralateral ACL injury based on pre-operative Tegner score, graft type, and injury side for soccer players vs. other female athletes. Wilcoxon rank-sum test was used to compare rate of subsequent ACL injury to patient age. Results: 337 patients met our inclusion/exclusion criteria (90 soccer players; 247 non-soccer playing athletes) with a mean age of 24.0 years. Of the 337 athletes, 6 were injured during professional competition, 43 were injured during collegiate athletics, 184 during high school play, and 136 during recreational athletics. No patient demographical differences were found at baseline between the soccer group and non-soccer group, including Tegner scores. Overall, 21 soccer players (23.3%) sustained a second ACL injury compared to 21 (8.5%) non-soccer athletes (P < 0.001). Soccer players had significantly more graft ruptures (10.0% vs. 2.0%, P = 0.003) and more contralateral ACL tears (13.3% vs. 6.5%, P = 0.04). Risk factors for ACL graft tear included young age (mean 16.0 vs 24.3 years; P < 0.0001) and higher Tegner Activity Level scores (mean 8.1 vs. 7.4, P = 0.049), but were not risk factors for contralateral ACL injury. Graft selection and injury side showed no statistical significance on graft rupture or contralateral injury. Conclusion: Female soccer players treated with ACL reconstruction had an increased rate of second ACL injury, including graft tear and contralateral ACL injury, compared to a similar group of non-soccer female athletes (23.3% vs. 8.5%, P < 0.001). In addition, young age and higher activity level were risk factors for graft rupture in this population.

Is MRI Subchondral Acetabular Edema or Cystic Change a Contraindication for Hip Arthroscopy in Patients with FAI

Objectives: Arthroscopic treatment for femoroacetabular impingement (FAI) generally has good results, but the outcome can worsen with increasing arthritis, largely defined as joint space narrowing. There remains a subset of hips with maintained joint space but with subchondral edema and cystic change of the acetabulum on MRI, with unknown outcome. Therefore, the purpose of this study was (1) to determine if postoperative outcome was worse for patients with subchondral edema on preoperative MRI compared to a matched control group and (2) to identify risk factors on MRI leading to inferior outcome. Methods: A review of patients who underwent arthroscopic hip surgery for FAI between 2007 and 2013 identified 530 patients. Of these, 39 patients had evidence of subchondral edema or subchondral cyst on the preoperative MRI with maintained joint space on preoperative radiographs. Lesions were characterized by grade, location and type using an established radiographic MRI classification system. A matched cohort of patients without evidence of subchondral edema or cyst was identified, and 2:1 matching was based on patient age, surgeon, surgery year within one year, surgical procedure, Tegner activity score, and Tonnis grade osteoarthritis changes on preoperative x-ray. Outcome was compared using the Hip Outcome Score and Modified Harris Hip Score between the two groups. Risk factors were then analyzed for type of lesion, grade and location of bone marrow lesion. Results: Thirty-nine patients (20 males, 19 females) showed preoperative MRI evidence of subchondral edema, and were followed for a mean of 23 months postoperatively (range, 12 - 60 months). Patients had an average age of 41 years (range, 19 - 67) and a preoperative Tegner score of 3.8 (range, 1 - 9). 87% of patients with subchondral cystic change had evidence of a grade IV full thickness cartilage lesion at the time of hip arthroscopy. Average Modified Harris Hip Scores were inferior for the subchondral group (79.9 ± 18.7) compared to the control group (86.6 ± 12.5; p = 0.027). In addition, Sport sub-scales of the Hip Outcome Score showed significantly lower scores for the subchondral group for both score (69.1 ± 27.0 vs. 79.5 ± 21.4, p = 0.018) and rating (66.7 ± 27.5 vs. 78.0 ± 20.8, p = 0.044). No radiographic risk factors, including type, location, or size of lesion were significant predictors of outcome. Two patients in the subchondral group were later converted to a total hip replacement. Conclusion: The presence of a subchondral acetabular cyst on MRI is indicative of a full thickness cartilage lesion at the time of arthroscopy. These patients have inferior outcomes for arthroscopic treatment of FAI compared to patients with similar age and activity level without MRI subchondral changes. Therefore, we recommend caution with consideration of hip arthroscopy in this patient subset.

Does Relief from Intra-articular Anesthetic Injection Predict Outcome after Hip Arthroscopy?

Objectives: Intra-articular (IA) anesthetic injection is commonly performed as a diagnostic test in the setting of femoroacetabular impingement (FAI). Currently, there is a paucity of data correlating post-injection pain relief and outcomes after hip arthroscopy for FAI. The purpose of this study is to determine whether the amount of pain relief after IA injection predicts clinical and functional outcomes following hip arthroscopy. We hypothesize that increased pain relief (>50%) will correlate with better outcomes after surgery. Methods: The records of patients undergoing hip arthroscopy for FAI at our institution between April 2007 and April 2012 were reviewed. We identified patients who underwent IA injection and subsequent hip arthroscopy. Inclusion criteria were: ultrasound or fluoroscopic guided intra-articular anesthetic injection performed at our institution, prospectively documented pre- and post-injection Numerical Rating Scale (NRS) pain scores, no prior ipsilateral hip surgery, and minimum 1 year follow-up. Pre-operative radiographs were reviewed and degree of osteoarthritis was determined using the Tonnis classification system. Outcomes were assessed with Modified Harris Hip Score (MHHS) and Hip Outcome Score (HOS). Univariate and multivariate models were performed to assess whether percent pain relief correlated with outcome scores. Results: 99 hips in 96 patients met our inclusion criteria and included 71 females (74%) and 25 males (26%) with a mean age of 37.5 ± 14.0 years. 26 patients had Tonnis grade 0, 55 had grade 1, and 18 had grade 2 (0 grade 3). Mean pain relief after IA injection was 73.6 ± 36.1 (range 0-100) percent. 26 patients (26%) had ≤50% pain relief while 73 (74%) had >50% pain relief. Outcome scores were obtained at a mean 14.9 months. Mean MHHS, HOS-ADL, 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 MHHS, HOS-ADL, or HOS-Sport scores. There was no significant difference in outcome scores between those with ≤50% and >50% pain relief. While patients that received >50% pain relief by IA injection were more likely to achieve positive results (MHHS >70) with a likelihood ratio of 1.23 (95% CI 0.92-1.53), this was not significant. Multivariate regression analysis demonstrated no significant predictors of outcome, including age, gender, Tonnis grade, percent relief with IA injection, number of months postoperatively, or type of surgery. Conclusion: In patients undergoing hip arthroscopy for FAI, our data indicates that the amount of pain relief from IA injection is a poor predictor of short term outcome, even when adjusting for chondral degeneration. While anesthetic injections can be an important diagnostic tool in select patients, correlation of the clinical history, physical examination, and imaging findings are fundamental. In addition, outcome following hip arthroscopy remains multifactorial.