Thomas D. Rosenberg

Infrapatellar contracture syndrome. An unrecognized cause of knee stiffness with patella entrapment and patella infera.

Infrapatellar Contracture Syndrome (IPCS) is an infre quently recognized cause of posttraumatic knee mor bidity. Unique to this group of patients is the combina tion of restricted knee extension and flexion associated with patella entrapment. IPCS can occur primarily as an exaggerated pathologic fibrous hyperplasia of the anterior soft tissues of the knee beyond that associated with normal healing. It can also occur secondarily to prolonged immobility and lack of extension associated with knee surgery, particularly intraarticular ACL recon struction. IPCS follows a predictable natural history which is divided into three stages. Symptoms, diagnos tic findings, and recommended treatment are deter mined by the stage at presentation. Once beyond its early presentation, IPCS is best treated by an anterior intraarticular and extraarticular capsular debridement and release, followed by extensive rehabilitation. The authors review 28 consecutive cases of IPCS. At fol lowup 3 months to 4 years postoperation, the patients had averaged 2.3 additional surgical procedures follow ing their index procedure or injury. The average increase in extension at followup was 12° with the average increase flexion 35°. Eighty per cent of patients demonstrated signs and symptoms consistent with patellofemoral arthrosis; 16% of the patients demonstrated patella infera. The authors con clude that prevention or early detection and aggressive treatment are the only ways of avoiding complication in these problem cases.

Extensor mechanism function after patellar tendon graft harvest for anterior cruciate ligament reconstruction

We evaluated extensor mechanism function in 10 pa tients after they had arthroscopically assisted ACL reconstruction using the central third of the patellar tendon. The patients were randomly selected 12 to 24 months after reconstruction. All had rehabilitation where range of motion was initiated within the 1 st postoperative week. All patients stated that they were satisfied and considered their knee to be stable. The KT-1000 maximum measurements (30 to 40 pounds) averaged an increase of 1.7 mm when compared with the opposite knee. Subjective complaints, such as an terior knee pain, grating, and weakness, were common and only 3 of 10 patients returned to all of their preinjury sports.Persistent radiographic abnormalities were common. Physical examination and functional testing also re vealed persistent dysfunction of the extensor mecha nism in patients with radiographic abnormalities. Isoki netic testing at 60 deg/sec showed an average quad riceps deficit of 18% compared to the normal extremity. Axial co...We evaluated extensor mechanism function in 10 pa tients after they had arthroscopically assisted ACL reconstruction using the central third of the patellar tendon. The patients were randomly selected 12 to 24 months after reconstruction. All had rehabilitation where range of motion was initiated within the 1 st postoperative week. All patients stated that they were satisfied and considered their knee to be stable. The KT-1000 maximum measurements (30 to 40 pounds) averaged an increase of 1.7 mm when compared with the opposite knee. Subjective complaints, such as an terior knee pain, grating, and weakness, were common and only 3 of 10 patients returned to all of their preinjury sports. Persistent radiographic abnormalities were common. Physical examination and functional testing also re vealed persistent dysfunction of the extensor mecha nism in patients with radiographic abnormalities. Isoki netic testing at 60 deg/sec showed an average quad riceps deficit of 18% compared to the normal extremity. Axial computed tomography scans revealed significant decrease in quadriceps cross-sectional area. Magnetic resonance imaging and computed tomography con firmed persistent defects at the harvest site; there was significant anterior knee scar formation in these pa tients. Despite achieving ligamentous stability, patients still experienced permanent weakness, functional deficits, patellar chondrosis, and pain after ACL reconstruction using the central one-third of the patellar tendon.

Lateral release of the patella: Indications and contraindications:

Charts were reviewed on patients at the Salt Lake Knee and Sports Medicine Clinic who had had a lateral release of the patella. Patients were divided into two groups. Group I contained patients who were entirely satisfied with the procedure, and Group II included patients who were complete failures (defined as a need for further surgical procedures). In Group I, 74 patients were included in the subjective followup. Forty of the 74 patients also had an objective followup, including roentgenograms and a physical examination. Group II contained 43 patients. Results indicated that the most predictable criterion for success was a negative passive patellar tilt. Secondary criteria included a medial and lateral patellar glide of two quadrants or less and a normal tubercle-sulcus angle at 90° of flexion. Patients had less predictable results after an isolated lateral release with a positive (greater than 5°) passive patellar tilt and a three quadrant or greater medial and lateral patellar glide or an abnormal tubercle-sulcus angle at 90° of flexion.

Detailed Analysis of Patients with Bilateral Anterior Cruciate Ligament Injuries

To better understand anatomic and other possible pre disposing factors for anterior cruciate ligament injuries, we retrospectively studied 31 patients with noncontact, bilateral injuries of this ligament. The 31 patients were carefully matched by age, sex, height, weight, and ac tivity level with 23 control subjects who had no history of knee injury. All 54 subjects underwent a full clinical knee examination, joint hypermobility tests, a hamstring tightness assessment, a computerized tomography scan analysis, and a plain view radiographic analysis, and were asked to provide a complete immediate-family history of knee ligament injury. In addition, the 31 pa tients in the experimental group underwent a KT-1000 arthrometer knee laxity examination and were also asked to provide an injury profile, including mechanism of injury, treatment received for each injury, and the time interval between injuries. Measurements obtained from the computerized tomography scan analysis demon strated a significantly wider lateral femoral condyle in the experimental group compared with the control group, indicating that certain anatomic factors may pre dispose people to anterior cruciate ligament injury. A significant difference was also found in the incidence rate of anterior cruciate ligament injury in the family his tory of the experimental group compared with the con trol group, indicating a possible congenital aspect of this injury.

The GORE-TEX anterior cruciate ligament prosthesis A long-term followup

The GORE-TEX anterior cruciate ligament prosthesis has been implanted in 268 patients at our institution since April of 1984. Follow-up for this study was avail able on 70% of these patients (188). Eighty-one percent (152) of these had the ligament for chronic injuries, 14% (26) for acute, and 5% (10) for subacute injuries. The patient population had an average age of 27.6 years (SD = 8.4) and a Tegner activity score of 6.05 (SD = 1.53). Prior procedures had been performed on 56% (105) of the patients. Concomitant procedures were performed in 73% (137) and included iliotibial band tenodesis, partial meniscectomy, posterior oblique lig ament advancement, or meniscal repair. Followup av eraged 48 months (range, 24 to 68). Evaluation included a questionnaire, physical examination, radiographs, KT- 1000 arthrometer testing, and an activity score. Results were graded as excellent, good, fair, and poor. Acceptable results (good and excellent) were obtained in 83 patients (44%). Fifty-eight patients (32%) were rated excellent and 25 (13%) were rated good. Unacceptable results (fair and poor) were obtained in 105 patients (56%). Twenty-five patients (13%) were rated fair and 80 (42%) were rated poor. Subjective improvement was indicated by 166 patients (88%). Activity levels postoperatively as rated by the Tegner Scale improved in 2 (1 %), remained the same in 167 (89%), and decreased in 19 patients (10%). Effusions occurred in 63 patients (34%) and caused an unac ceptable result in 22 (12%). Rupture occurred in 23 patients (12%). Loosening greater than 3 mm occurred in 64 patients (34%) and led to unacceptable results in 37 (20%). Infection occurred in 5 patients (2.7%). Ex cellent results had a statistically significantly higher age and lower activity score than the poor results (P = 0.045 and 0.012, respectively). The patients with pre vious intraarticular reconstructions had a 76% unac ceptable rating (16 of 21).

Strain in the human medial collateral ligament during valgus loading of the knee

The medial collateral ligament is one of the most frequently injured ligaments in the knee. Although the medial collateral ligament is known to provide a primary restraint to valgus and external rotations, details regarding its precise mechanical function are unknown. In this study, strain in the medial collateral ligament of eight knees from male cadavers was measured during valgus loading. A material testing machine was used to apply 10 cycles of varus and valgus rotation to limits of ±10.0 N-m at flexion angles of 0°, 30°, 60°, and 90°. A three-dimensional motion analysis system measured local tissue strain on the medial collateral ligament surface within 12 regions encompassing nearly the entire medial collateral ligament surface. Results indicated that strain is significantly different in different regions over the surface of the medial collateral ligament and that this distribution of strain changes with flexion angle and with the application of a valgus torque. Strain in the posterior and central portions of the medial collateral ligament generally decreased with increasing flexion angle, whereas strain in the anterior fibers remained relatively constant with changes in flexion angle. The highest strains in the medial collateral ligament were found at full extension on the posterior side of the medial collateral ligament near the femoral insertion. These data support clinical findings that suggest the femoral insertion is the most common location for medial collateral ligament injuries.

Quadrupled Semitendinosus Anterior Cruciate Ligament Reconstruction: 5-Year Results in Patients Without Meniscus Loss

PURPOSE The purpose of this study was to determine the mid-term (minimum 5-year) results of isolated primary anterior cruciate ligament (ACL) reconstructions with intact or repaired menisci. TYPE OF STUDY Case series. METHODS Of 184 ACL reconstructions from April 1990 to February 1992, 33 initially met the inclusion criteria of primary reconstruction with quadrupled semitendinosus tendon and without extra-articular reconstruction or meniscus removal. Patients with known traumatic rerupture of the graft with revision (1 case) or subsequent meniscectomy (1 case) were excluded from the study. Twenty of the remaining 31 patients were available for follow-up at an average of 5.7 years after surgery. At follow-up, a comprehensive knee examination, KT-1000 arthrometry, radiography, functional testing, and isokinetic strength testing were performed. A subjective questionnaire, Tegner scale, and IKDC evaluation were administered as well. Four patients who were unable to come in for follow-up returned a knee-assessment questionnaire. RESULTS Arthrometric anterior tibial translation was reduced from a preoperative average of 6.3 +/- 2.8 mm (manual maximum side-to-side difference) to an average of 0.0 +/- 1.3 mm (range, -2.5 to 2 mm). Radiographically, 1 patient experienced mild narrowing in the lateral compartment. Tegner activity level was maintained at the preinjury level in nearly half the patients. Isokinetic strength deficits were less than 10%; 17 (85%) of the patients had a normal or nearly normal result as graded by the IKDC scoring system. CONCLUSIONS The above data show minimal morbidity, a low reoperation rate, and excellent clinical outcome. Because the stability of the knee persists beyond 5 years after ACL reconstruction, patients are able to maintain preinjury activity levels without reinjury.

The biomechanics of lateral knee bracing Part I: Response of the valgus restraints to loading

To better understand the role of preventive knee braces in injury prevention, a biomechanical study using fresh frozen cadaveric knees (N = 18) was conducted. Liga ment tensions and joint displacements were measured at static, nondestructive valgus forces as well as low- rate destructive forces. After quantifying and establish ing individual ligament contributions to valgus restrain ing function, knees were then braced with two different laterally applied preventive braces, the McDavid Knee Guard and the Omni Anderson Knee StabIer.The effects of lateral bracing were analyzed according to valgus force, joint line opening, and ligament tensions. Valgus applied forces, with or without braces, consis tently produced medial collateral ligament (MCL) disrup tions at ligament tensions surprisingly higher than the anterior cruciate ligament (ACL) and higher than or equal to the posterior cruciate ligament (PCL). Although large joint displacements were necessary for complete ligament failure, bundle disruption in the MCL, ACL, and PCL was noted at much smaller joint openings. In Part I of this study, no significant protection could be documented with the two preventive braces used. Also, four potentially adverse effects were noted: MCL pre load, center axis shift, premature joint line contact, and brace slippage.

Discoid lateral meniscus: case report of arthroscopic attachment of a symptomatic Wrisberg-ligament type

The symptomatic discoid lateral meniscus is a well-known congenital anomaly that is of three different types: complete, incomplete, and Wrisberg-ligament type. The Wrisberg-ligament type has no meniscotibial attachment posteriorly, and in the past has been treated by total (open or arthroscopic) meniscectomy. In this article, we review the literature and report a previously unreported case of arthroscopic peripheral attachment after central partial meniscectomy of a Wrisberg-ligament type discoid lateral meniscus, with documentation of healing at arthroscopic second look 1 year following surgery.

The Incidence of Deep Venous Thrombosis After Arthroscopic Knee Surgery

We retrospectively reviewed the records of 2050 arthroscopic knee surgeries performed at The Orthopedic Specialty Hospital from January 1993 to December 1994. The number of clinically detected deep venous thromboses, with confirmation by duplex ultrasonography, was determined. Prospectively, preoperative and postoperative duplex ultrasonographic images were completed on 239 patients divided into 2 groups: those undergoing nonligament, intraarticular arthroscopic surgery (N 131) and those undergoing arthroscopically assisted ligament surgery and extraarticular or osteotomy surgery (N 108). For the retrospective study, the incidence of deep venous thrombosis was 0.24%. Prospectively, seven total deep venous thromboses were identified (rate, 2.9%), with five being identified within 8 days of surgery in asymptomatic patients (rate, 2.1%). There were no statistically significant associations or correlations between the development of deep venous thrombosis and patient personal data or surgical variables, respectively. The difference in the rate of deep venous thrombosis between the two prospective groups was not statistically significant; however, patients who had more invasive surgery tended to be at higher risk for developing deep venous thrombosis. A cost-benefit analysis did not support the routine use of duplex ultrasonography to detect deep venous thrombosis in patients undergoing arthroscopic knee surgery.