Robert W. Frederick

Evaluation of the Intraosseous and Extraosseous Blood Supply to the Distal Femoral Condyles

Osteonecrosis of the distal femur occurs more often in the medial femoral condyle than in the lateral femoral condyle, but the vascular supply to these regions has not previously been described. Twelve fresh adult cadaver legs were injected with india ink or latex via the femoral artery and then meticulously dissected to evaluate the extraosseous blood supply. After all soft tissue was removed, the intraosseous blood supply was evaluated using a modified Spateholtz technique. The vascular structures at risk during posterior cruciate ligament reconstruction were also identified. The analysis of the extraosseous arterial supply demonstrated that the superior and inferior lateral genicular arteries combine to supply the lateral femoral condyle. The medial femoral condyle is supplied primarily by the superior medial genicular artery and other lesser branches of the popliteal artery. The intraosseous supply to the lateral condyle was shown to consist of an arcade of vessels providing multiple branches to the subchondral bone with no obvious “watershed” region of limited vascularity. The intraosseous supply to the medial condyle appeared to consist of a single nutrient vessel supplying the subchondral bone with an apparent watershed area of limited supply. A potentially significant difference exists between the intraosseous and extraosseous blood supply to the medial and lateral femoral condyles that may explain the higher frequency of ischemic events occurring in the medial femoral condyle. The close proximity of the extraosseous vessels to the medial femoral condyle and the standard femoral tunnel used during posterior cruciate ligament reconstruction may explain the occurrence of avascular necrosis after this procedure.

Effect of Graft Choice on the Outcome of Revision Anterior Cruciate Ligament Reconstruction in the Multicenter ACL Revision Study (MARS) Cohort

Background: Most surgeons believe that graft choice for anterior cruciate ligament (ACL) reconstruction is an important factor related to outcome; however, graft choice for revision may be limited due to previously used grafts. Hypotheses: Autograft use would result in increased sports function, increased activity level, and decreased osteoarthritis symptoms (as measured by validated patient-reported outcome instruments). Autograft use would result in decreased graft failure and reoperation rate 2 years after revision ACL reconstruction. Study Design: Cohort study; Level of evidence, 2. Methods: Patients undergoing revision ACL reconstruction were identified and prospectively enrolled by 83 surgeons at 52 sites. Data collected included baseline demographics, surgical technique, pathologic abnormalities, and the results of a series of validated, patient-reported outcome instruments (International Knee Documentation Committee [IKDC], Knee injury and Osteoarthritis Outcome Score [KOOS], Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], and Marx activity rating score). Patients were followed up at 2 years and asked to complete the identical set of outcome instruments. Incidences of additional surgery and reoperation due to graft failure were also recorded. Multivariate regression models were used to determine the predictors (risk factors) of IKDC, KOOS, WOMAC, Marx scores, graft rerupture, and reoperation rate at 2 years after revision surgery. Results: A total of 1205 patients (697 [58%] males) were enrolled. The median age was 26 years. In 88% of patients, this was their first revision, and 341 patients (28%) were undergoing revision by the surgeon who had performed the previous reconstruction. The median time since last ACL reconstruction was 3.4 years. Revision using an autograft was performed in 583 patients (48%), allograft was used in 590 (49%), and both types were used in 32 (3%). Questionnaire follow-up was obtained for 989 subjects (82%), while telephone follow-up was obtained for 1112 (92%). The IKDC, KOOS, and WOMAC scores (with the exception of the WOMAC stiffness subscale) all significantly improved at 2-year follow-up (P < .001). In contrast, the 2-year Marx activity score demonstrated a significant decrease from the initial score at enrollment (P < .001). Graft choice proved to be a significant predictor of 2-year IKDC scores (P = .017). Specifically, the use of an autograft for revision reconstruction predicted improved score on the IKDC (P = .045; odds ratio [OR] = 1.31; 95% CI, 1.01-1.70). The use of an autograft predicted an improved score on the KOOS sports and recreation subscale (P = .037; OR = 1.33; 95% CI, 1.02-1.73). Use of an autograft also predicted improved scores on the KOOS quality of life subscale (P = .031; OR = 1.33; 95% CI, 1.03-1.73). For the KOOS symptoms and KOOS activities of daily living subscales, graft choice did not predict outcome score. Graft choice was a significant predictor of 2-year Marx activity level scores (P = .012). Graft rerupture was reported in 37 of 1112 patients (3.3%) by their 2-year follow-up: 24 allografts, 12 autografts, and 1 allograft and autograft. Use of an autograft for revision resulted in patients being 2.78 times less likely to sustain a subsequent graft rupture compared with allograft (P = .047; 95% CI, 1.01-7.69). Conclusion: Improved sports function and patient-reported outcome measures are obtained when an autograft is used. Additionally, use of an autograft shows a decreased risk in graft rerupture at 2-year follow-up. No differences were noted in rerupture or patient-reported outcomes between soft tissue and bone–patellar tendon–bone grafts. Surgeon education regarding the findings of this study has the potential to improve the results of revision ACL reconstruction.

Femoral, Saphenous Nerve Palsy After Tourniquet Use: A Case Report

Persistent motor and sensory abnormalities after surgery may affect the rehabilitation process. Patients with continued weakness may be perceived as lacking motivation by health care providers. However, there may be an underlying pathophysiologic abnormality preventing patients from progressing through their rehabilitation programs. We report a case of a 20-year-old man who underwent surgical repair of multiple knee structures with the use of a pneumatic tourniquet. Several weeks after surgery, electromyographic evaluation was done because he was having difficulty in his rehabilitation because of persistent weakness. An electromyography and nerve conduction study (NCS) revealed femoral and saphenous nerve palsies. Our report is the first on tourniquet-induced saphenous nerve injury as well as on abnormal femoral NCSs caused by tourniquet use. A review of the literature indicates that tourniquet-induced nerve palsies are not a rare event. Further evaluation should be considered if patients who are having persistent weakness or sensory findings after surgery have used a tourniquet.

Osteoarthritis classification scales: Interobserver reliability and arthroscopic correlation

BACKGROUND Osteoarthritis of the knee is commonly diagnosed and monitored with radiography. However, the reliability of radiographic classification systems for osteoarthritis and the correlation of these classifications with the actual degree of confirmed degeneration of the articular cartilage of the tibiofemoral joint have not been adequately studied. METHODS As the Multicenter ACL (anterior cruciate ligament) Revision Study (MARS) Group, we conducted a multicenter, prospective longitudinal cohort study of patients undergoing revision surgery after anterior cruciate ligament reconstruction. We followed 632 patients who underwent radiographic evaluation of the knee (an anteroposterior weight-bearing radiograph, a posteroanterior weight-bearing radiograph made with the knee in 45° of flexion [Rosenberg radiograph], or both) and arthroscopic evaluation of the articular surfaces. Three blinded examiners independently graded radiographic findings according to six commonly used systems-the Kellgren-Lawrence, International Knee Documentation Committee, Fairbank, Brandt et al., Ahlbäck, and Jäger-Wirth classifications. Interobserver reliability was assessed with use of the intraclass correlation coefficient. The association between radiographic classification and arthroscopic findings of tibiofemoral chondral disease was assessed with use of the Spearman correlation coefficient. RESULTS Overall, 45° posteroanterior flexion weight-bearing radiographs had higher interobserver reliability (intraclass correlation coefficient = 0.63; 95% confidence interval, 0.61 to 0.65) compared with anteroposterior radiographs (intraclass correlation coefficient = 0.55; 95% confidence interval, 0.53 to 0.56). Similarly, the 45° posteroanterior flexion weight-bearing radiographs had higher correlation with arthroscopic findings of chondral disease (Spearman rho = 0.36; 95% confidence interval, 0.32 to 0.39) compared with anteroposterior radiographs (Spearman rho = 0.29; 95% confidence interval, 0.26 to 0.32). With respect to standards for the magnitude of the reliability coefficient and correlation coefficient (Spearman rho), the International Knee Documentation Committee classification demonstrated the best combination of good interobserver reliability and medium correlation with arthroscopic findings. CONCLUSIONS The overall estimates with the six radiographic classification systems demonstrated moderate (anteroposterior radiographs) to good (45° posteroanterior flexion weight-bearing radiographs) interobserver reliability and medium correlation with arthroscopic findings. The International Knee Documentation Committee classification assessed with use of 45° posteroanterior flexion weight-bearing radiographs had the most favorable combination of reliability and correlation. LEVEL OF EVIDENCE Diagnostic Level I. See Instructions for Authors for a complete description of levels of evidence.

Perioperative Compartment Syndrome. A Report Of Four Cases

Compartment syndromes are usually seen following trauma to or arterial reconstruction of an extremity13,14,17,21,26,27. Since the mid-1970s, major improvements have been made in the devices used to irrigate wounds and joints and to infuse fluids. Occasionally, the use of pressurized devices to enhance the flow of fluid may be associated with the development of acute compartment syndromes. We report the cases of four patients in whom an acute compartment syndrome developed during an operative procedure and in whom a large amount of extravasated fluid was found in the soft tissue of the extremity that had been operated on. The compartment syndromes were believed to have resulted from the use of a pressurized pulsatile irrigation system (two patients), the use of a pump for the infusion of fluids into the joint during an arthroscopic procedure (one patient), and the use of a device for the pressurized intravenous infusion of parenteral fluids (one patient). We retrospectively reviewed the hospital records for each patient and obtained information about the nature of the original injury, the interval of time before the compartment syndrome developed, the reasons that a compartment syndrome was suspected, the method for the measurement of tissue pressure, and the treatment of the compartment syndrome. At the most recent follow-up evaluation, all four patients were examined by one of us to determine the functional outcome. CASE 1. A fifty-seven-year-old man who was right-hand dominant sustained a direct blow to the ulnar aspect of the right forearm, resulting in an open fracture of the diaphysis of the ulna; the defect of the skin was less than two centimeters. There was no clinical evidence of a compartment syndrome at the time of presentation. Approximately twelve hours after the injury, the patient was …

Kerlan-Jobe Orthopaedic Clinic overhead athlete scores in asymptomatic professional baseball pitchers.

BACKGROUND The Kerlan-Jobe Orthopaedic Clinic (KJOC) Shoulder and Elbow score is a subjective questionnaire that has been validated and been shown to be more specific in overhead athletes than the American Shoulder and Elbow Surgeons scale. The purpose of this study was to determine a mean KJOC score and reasonable range of KJOC scores within which a healthy asymptomatic professional baseball pitcher will fall. It was hypothesized that healthy professional baseball pitchers would have very high KJOC scores. MATERIALS AND METHODS KJOC questionnaires were given to all healthy pitchers before the start of the season at all levels in 1 professional Minor League system. Pitchers were asked to complete the questionnaire upon reporting to their AAA, AA, or A affiliate team. Any pitcher starting the season on the disabled list was excluded from the study. RESULTS KJOC scores were returned by 44 pitchers. The mean score for all pitchers was 94.82 (95% confidence interval, 92.94-96.70). The mean score for each question was greater than 9 of 10. The mean score for the AAA affiliate was significantly higher than that for the AA affiliate (P = .015). No other significant differences in scores were found between class levels or groups based on professional playing experience. CONCLUSION Only 7 of 44 healthy asymptomatic pitchers (16%) had a KJOC score below 90. Therefore, we believe that the KJOC score is an accurate assessment for overhead athletes and normal values should be greater than 90. Anything below this value could be a potential cause for concern for team physicians. LEVEL OF EVIDENCE Basic Science, Survey Study, Healthy Subjects.

Meniscal and Articular Cartilage Predictors of Clinical Outcome After Revision Anterior Cruciate Ligament Reconstruction

Background: Revision anterior cruciate ligament (ACL) reconstruction has been documented to have worse outcomes compared with primary ACL reconstructions. Purpose/Hypothesis: The purpose of this study was to determine if the prevalence, location, and/or degree of meniscal and chondral damage noted at the time of revision ACL reconstruction predicts activity level, sports function, and osteoarthritis symptoms at 2-year follow-up. The hypothesis was that meniscal loss and high-grade chondral damage noted at the time of revision ACL reconstruction will result in lower activity levels, decreased sports participation, more pain, more stiffness, and more functional limitation at 2 years after revision surgery. Study Design: Cohort study; Level of evidence, 2. Methods: Between 2006 and 2011, a total of 1205 patients who underwent revision ACL reconstruction by 83 surgeons at 52 hospitals were accumulated for study of the relationship of meniscal and articular cartilage damage to outcome. Baseline demographic and intraoperative data, including the International Knee Documentation Committee (IKDC) subjective knee evaluation, Knee injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Marx activity score, were collected initially and at 2-year follow-up to test the hypothesis. Regression analysis was used to control for age, sex, body mass index, smoking status, activity level, baseline outcome scores, revision number, time since last ACL reconstruction, incidence of having a previous ACL reconstruction on the contralateral knee, previous and current meniscal and articular cartilage injury, graft choice, and surgeon years of experience to assess the meniscal and articular cartilage risk factors for clinical outcomes 2 years after revision ACL reconstruction. Results: At 2-year follow-up, 82% (989/1205) of the patients returned their questionnaires. It was found that previous meniscal injury and current articular cartilage damage were associated with the poorest outcomes, with prior lateral meniscectomy and current grade 3 to 4 trochlear articular cartilage changes having the worst outcome scores. Activity levels at 2 years were not affected by meniscal or articular cartilage pathologic changes. Conclusion: Prior lateral meniscectomy and current grade 3 to 4 changes of the trochlea were associated with worse outcomes in terms of decreased sports participation, more pain, more stiffness, and more functional limitation at 2 years after revision surgery, but they had no effect on activity levels. Registration: NCT00625885

Surgical Restoration/Repair of Articular Cartilage Injuries in Athletes

Abstract Articular cartilage injuries of the knee are an increasingly common source of pain and dysfunction, particularly in the athletic population. In the athlete, untreated articular cartilage defects can represent a career threatening injury and create a significant obstacle in returning to full athletic participation. The markedly limited healing potential of articular cartilage often leads to continued deterioration and progressive functional limitations. Numerous studies have shown that full thickness articular cartilage lesions are frequently encountered at the time of arthroscopy, particularly associated with athletic injury. A variety of surgical treatment options exist, including debridement, microfracture, osteochondral autograft, osteochondral allograft, and autologous chondrocyte implantation. Each technique has advantages and limitations for restoring articular cartilage function, and emerging technology continues to improve the results of treatment. Our article provides an evidence-based review on the etiology and prevalence of articular cartilage injuries in athletes, along with the principles and techniques available for restoring articular cartilage function following injury.

Pectoralis Major Ruptures in Professional American Football Players

Abstract Background: Pectoralis major injuries are an infrequent shoulder injury that can result in pain, weakness, and deformity. These injuries may occur during the course of an athletic competition, including football. The purpose of this study was to determine the incidence of pectoralis major ruptures in professional football players and time lost from the sport following injury. We hypothesized that ruptures most frequently occur during bench-press strength training. Methods: The National Football League Injury Surveillance System was reviewed for all pectoralis major injuries in all players from 2000 to 2010. Details regarding injury setting, player demographics, method of treatment, and time lost were recorded. Results: A total of 10 injuries—complete ruptures—were identified during this period. Five of the 10 were sustained in defensive players, generally while tackling. Nine occurred during game situations, and 1 occurred during practice. Specific data pertinent to the practice injury was not available. No rupture occurred during weight lifting. Eight ruptures were treated operatively, and 2 cases did not report the method of definitive treatment. The average days lost was 111 days (range, 42–189). The incidence was 0.004 pectoralis major ruptures during the 11-year study period. Conclusions: Pectoralis major injuries are uncommon while playing football. In the National Football League, these injuries primarily occur not during practice or while bench pressing but rather during games. When pectoralis major ruptures do occur, they are successfully treated operatively. Surgery may allow for return to full sports participation. Level of Evidence: IV, case series.

Approach to the Active Patient with Chronic Anterior Knee Pain

Abstract The diagnosis and management of chronic anterior knee pain in the active individual can be frustrating for both the patient and physician. Pain may be a result of a single traumatic event or, more commonly, repetitive overuse. “Anterior knee pain,” “patellofemoral pain syndrome,” and “chondromalacia” are terms that are often used interchangeably to describe multiple conditions that occur in the same anatomic region but that can have significantly different etiologies. Potential pain sources include connective or soft tissue irritation, intra-articular cartilage damage, mechanical irritation, nerve-mediated abnormalities, systemic conditions, or psychosocial issues. Patients with anterior knee pain often report pain during weightbearing activities that involve significant knee flexion, such as squatting, running, jumping, and walking up stairs. A detailed history and thorough physical examination can improve the differential diagnosis. Plain radiographs (anteroposterior, anteroposterior flexion, lateral, and axial views) can be ordered in severe or recalcitrant cases. Treatment is typically nonoperative and includes activity modification, nonsteroidal anti-inflammatory drugs, supervised physical therapy, orthotics, and footwear adjustment. Patients should be informed that it may take several months for symptoms to resolve. It is important for patients to be aware of and avoid aggravating activities that can cause symptom recurrence. Patients who are unresponsive to conservative treatment, or those who have an underlying systemic condition, should be referred to an orthopedic surgeon or an appropriate medical specialist.