Intra-articular mechanical blocks and full extension in patients undergoing anterior cruciate ligament reconstruction.

Patients with acute anterior cruciate ligament (ACL) rupture frequently present with a lack of full extension. Current literature is unclear whether arthroscopic debridement is necessary before reconstruction to achieve full extension postoperatively. This study examined the postoperative extension achieved in 153 knees that underwent ACL reconstruction within 12 weeks of index injury. All patients performed preoperative physical therapy to increase range of motion and control pain/swelling, regardless of presenting range of motion without prior aspiration or arthroscopy. Of the 153 knees, 103 had meniscal pathology, of which 73 were peripheral vertical tears; 96 of the 153 knees lacked >/=3 degrees extension preoperatively. Five of 96 knees had an intra-articular mechanical block to extension and all regained full extension after ACL reconstruction. This study documented that a true intra-articular mechanical block is unusual in primary ACL ruptures. Lack of full extension can be adequately dealt with during surgical reconstruction without a detrimental effect on knee extension postoperatively.     

Return of motion after simultaneous repair of displaced bucket-handle meniscal tears and anterior cruciate ligament reconstruction.

Patients with displaced bucket-handle (DBH) meniscal tears in anterior cruciate ligament (ACL)-deficient knees are prone to flexion contracture following meniscal repair and simultaneous ACL reconstruction. It has been suggested that ACL reconstruction be delayed until full range of motion has returned after the meniscal repair. A retrospective analysis was performed comparing the return of extension in patients undergoing simultaneous ACL reconstruction and repair of DBH tears (group A) versus a control group of patients with non-DBH tears (group B). Age, sex, body mass index, duration of time from injury to surgery, and preoperative extension were also compared between groups and evaluated for their significance as risk factors. Patients in group A achieved recovery to -5 degrees and 0 degrees of extension 22% and 35% more slowly, respectively, when compared with group B. These differences were not statistically significant. Female patients tended to heal more rapidly in both groups. We conclude that a one-stage procedure is sufficient in allowing patients with DBH tears in ACL-deficient knees to regain a functional knee to within 5 degrees of full extension.     

关节镜下前交叉韧带重建术后膝关节感染的临床诊断与治疗

目的 探讨前交叉韧带重建术后膝关节感染的临床诊断与治疗方法.方法 回顾性研究1997年1月至2007年7月关节镜下前交叉韧带重建术后膝关节感染的患者,通过对术后关节感染的发病率、危险因素、临床表现、实验室检查结果、治疗方法及临床预后情况的观察,分析总结临床诊断与治疗方法.结果 关节镜下前交叉韧带重建手术共3638例,术后关节感染者16例,感染率0.44%.临床表现有体温增高,膝关节肿胀、疼痛,关节活动度受限.细菌培养阳性11例,以表皮葡萄球菌最多见.治疗包括静脉抗炎、关节冲洗注药、关节镜下清理术等方法,所有患者均治愈.清创术后1年以上的12例患者中失访3例,9例术后获得随访,随访时间平均19.7个月,膝关节活动度及韧带功能良好.结论 前交叉韧带重建术后膝关节感染的发牛率较低,但可能会导致关节功能障碍、软骨破坏及韧带移植物失效等严重后果.因此早期诊断、早期治疗尤为重要.尽早行关节镜下清理手术,术后结合抗生素治疗,辅以积极有效的功能康复,可以取得很好的临床效果.     

The cyclops lesion: a cause of diminished knee extension after rupture of the anterior cruciate ligament.

Four patients presented with persistent diminution of knee motion after rupture of the anterior cruciate ligament with a novel lesion as the cause. Each had participated in an aggressive rehabilitation program for a minimum of 2 months with emphasis on regaining full range of knee motion. Because chronic impairment of knee extension can be disabling, in those who did not regain full range of motion, arthroscopy of the knee ensued. All had a lesion in the intercondylar notch near the tibial insertion of the anterior cruciate ligament that acted as a mechanical obstruction to full knee extension. Grossly and histologically, these were similar to the cyclops lesion that also has been shown to cause loss of knee extension after anterior cruciate ligament reconstruction. Arthroscopic debridement of the cyclops lesion and manual manipulation of the knee under anesthesia lead to restoration of full knee extension in all knees. In 1 other knee with chronic instability after anterior cruciate ligament rupture, the cyclops lesion was present but was very small and was not associated with diminished knee extension. When loss of full extension persists for 2 months after anterior cruciate ligament disruption despite aggressive rehabilitation, the presence of a cyclops lesion should be considered.     

Knee biomechanics after UKA and its relation to the ACL--a robotic investigation.

Unicompartmental knee arthroplasty (UKA) has regained popularity in recent years. However, limited data exist on how UKA affects knee biomechanics. The role of the anterior cruciate ligament (ACL) after fixed bearing UKA remains controversial. In this study, a robotic testing system was used to apply a quadriceps/hamstrings load to cadaveric knee specimens in the intact state, after medial UKA, and after transection of the ACL in UKA. The load was applied to the knee from full extension to 120 degrees of flexion in 30 degrees increments. UKA generally did not affect anterior-posterior (AP) femoral position, but did cause external tibial rotation and variations in varus-valgus rotation compared to the intact knee. ACL transection after UKA shifted the femur posteriorly compared to the intact and UKA knees and increased internal tibial rotation compared to the UKA knee at low flexion. The AP motion of the articular contact position in the implant was increased after ACL transection. These data might help explain the mechanism of tibial component loosening and provide insight into further investigations of polyethylene wear in UKA. Based on the kinematic data, the ACL should be functional to provide patients the greatest opportunity for long-term success after medial UKA.     

Cyclops syndrome: loss of extension following intra-articular anterior cruciate ligament reconstruction

Arthrofibrosis is one of the recognized complications following traditional anterior cruciate ligament (ACL) reconstruction. With the advent of arthroscopic assisted ACL reconstructions, the extent of potential arthrofibrosis appeared to be less. However, 13 patients after intra-articular ACL reconstruction using a patella tendon autograft developed a similar symptom complex. In addition to postoperative loss of full extension, there was an audible and palpable clunk with terminal extension. These patients had similar arthroscopic findings of a nodule that formed anterolateral to the tibial tunnel placement of the graft. The arthroscopic appearance of the soft tissue mass with its surface vessels was reminiscent of a "cyclops." After arthroscopy with debridement and manipulation of the knee, extension was improved in all cases. The average range of motion immediately after the procedure was 6.0-130 degrees, compared with 16-103 degrees preoperatively. The range of motion at last follow-up averaged 3.8 degrees of extension and 138 degrees of flexion. All patients had greater than 130 degrees of flexion. There were no complications attributed to the manipulation and arthroscopic lysis of adhesions, and no patient experienced loss of graft integrity or knee stability. The "cyclops" nodule was examined grossly and microscopically and demonstrated peripheral fibrous tissue with a central region of granulation tissue in all specimens. In addition, two specimens were noted to include bony fragments and three specimens contained cartilaginous tissue.     

Primary repair of knee dislocations: results in 25 patients (28 knees) at a mean follow-up of four years

OBJECTIVE: To investigate the outcomes of knee dislocations treated with primary repair and an early rehabilitation protocol. DESIGN: Retrospective. SETTINGS: Level 1 Trauma Center. PATIENTS: Consecutive patients with knee dislocation referred to a single surgeon for care between 1994 and 2002 were included, for a total of 27 patients with 30 knee dislocations. Twenty-five patients (28 knees) were evaluated by an independent observer at a mean of 48 months (13-82 months). INTERVENTION: All patients underwent primary repair of all injured ligaments using a consistent technique and early rehabilitation protocol. MAIN OUTCOME MEASUREMENTS: In addition to range of motion and stability assessment, Lysholm and Tegner scores were used to evaluate outcome. RESULTS: The mean post-operative Lysholm score was 89.0. Range of motion analysis for the 22 unilateral dislocations available for examination showed a mean extension loss of 1.9 degrees and mean flexion loss of 10.2 degrees , with a mean arc of motion of 119.3 degrees . Overall, the knees were found to be clinically stable. CONCLUSIONS: Primary repair of ligaments coupled with an early rehabilitation program provides comparable outcomes to published results of ligament reconstruction. Primary repair of ligaments in the dislocated knee should be considered as an effective option in the trauma population.     

Two-stage reconstruction with autografts for knee dislocations

Traumatic knee dislocations are severe injuries that involve damage to the anterior cruciate ligament, the posterior cruciate ligament, and the lateral or medial ligamentous structures. There are no established methods of treatment. The objective of the current study was to report the clinical outcome of a two-stage autologous reconstruction on nine knees (eight patients). The mean followup was 40.1 months. The first stage of the reconstruction was done at a mean of 2 weeks after the injury, and the posterior cruciate ligament was reconstructed by an arthroscopically assisted technique using contralateral autogenous hamstring tendon as the graft material. Three months later, the second stage of the reconstruction was done for the ligaments that had not healed with conservative treatment. Arthroscopically assisted anterior cruciate ligament reconstruction was done on all of the knees using the ipsilateral autogenous hamstring tendon or bone-patellar tendon-bone as the graft material. At the same time, a medial collateral ligament reconstruction using an autogenous semitendinosus tendon was done on one knee, and reconstruction of the posterolateral ligamentous structures using a biceps tendon was done on three knees. Each of the knees that was reconstructed was capable of full extension, and the mean degree of passive flexion was 139.5 degrees +/- 5.2 degrees. The mean side-to-side difference in anteroposterior total laxity (KT-1000 arthrometer, manual maximum) was 2.3 +/- 1.9 mm. None of the knees had lateral or medial instability. All of the injured ligaments were able to be reconstructed with autografts, and severe contracture was able to be prevented. A good clinical outcome can be achieved when two-stage reconstruction is used for traumatic knee dislocations.     

Primary repair of intraoperative disruption of the medical collateral ligament during total knee arthroplasty

BACKGROUND: Intraoperative disruption of the medial collateral ligament during total knee arthroplasty is an uncommon complication that is frequently treated by implanting a prosthesis with varus-valgus constraint. To our knowledge, no data have been published on primary repair or reattachment of the medial collateral ligament and implantation of a minimally constrained posterior-stabilized or cruciate-retaining prosthesis. This retrospective study evaluates the hypothesis that satisfactory clinical results, at a minimum of two years, can be achieved with immediate repair or reattachment of the medial collateral ligament and without a constrained total knee prosthesis. METHODS: Of 600 knees treated with primary total knee arthroplasty, sixteen (in fourteen patients) sustained either a midsubstance disruption of the medial collateral ligament or an avulsion of the ligament from bone during the procedure. Preoperatively, all patients had either neutral or varus alignment and an intact medial collateral ligament. Midsubstance tears were treated with direct primary repair, and avulsions of the ligament off the tibia or femur were treated with suture-anchor reattachment to bone. All patients wore a hinged knee brace, with no limit to the range of motion, for six weeks postoperatively. Clinical and radiographic data were gathered prospectively as part of a database that was ongoing throughout the period of study; the cohort of patients was assembled retrospectively by searching that database. RESULTS: No patients were lost to follow-up. The mean duration of follow-up was forty-five months (range, twenty-four to ninety-five months). The Hospital for Special Surgery knee scores increased from a mean of 47 points (poor) preoperatively to a mean of 93 points (excellent) at the time of final follow-up. On physical examination, no patient had a Hospital for Special Surgery score in the fair or poor range and all patients had regained normal stability in the coronal plane both at full extension and at 30 degrees of flexion. No patient required knee-bracing beyond the initial six-week postoperative period. The range of motion at the time of final follow-up averaged 108 degrees (range, 85 degrees to 125 degrees ), although one knee required manipulation under anesthesia to obtain a satisfactory range of motion. No arthroplasties required revision. Radiographic examination demonstrated appropriate limb alignment in all patients at the time of final follow-up. CONCLUSIONS: Intraoperative disruption of the medial collateral ligament can be treated with primary repair or reattachment of the ligament to bone and postoperative bracing with good results; this avoids the potential disadvantages associated with the use of varus-valgus constrained implants.     

Accelerated rehabilitation after anterior cruciate ligament reconstruction

Presented at the 15th annual meeting of the AOSSM, Traverse City, MI, July 1989. Address reprint requests to: K. Donald Shelbourne, MD, Methodist Sports Medicine Center, 1815 North Capitol Avenue, Suite 530, Indianapolis, IN 46202.To overcome many of the complications after ACL reconstruction (prolonged knee stiffness, limitation of complex extension, delay in strength recovery, anterior knee pain), yet still maintain knee stability, we developed a rehabilitation protocol that emphasizes full knee extension on the first postoperative day and immediate weightbearing according to the patient's tolerance. Of 800 patients who underwent intraarticuar ACL patellar tendon-bone graft reconstruction, performed by the same surgeon, the last 450 patients have followed the accelerated rehabilitation schedule as outlined in the protocol. A longer than 2 year followup is recorded for 73 of the patients in the accelerated rehabilitation group. On the 1st postoperative day, we encouraged these patients to walk with full weightbearing and full knee extension. By the 2nd postoperative week, the patients with a 100 degrees range of motion participated in a guided exercise and strengthening program. By the 4th week, patients were permitted unlimited activities of daily living and were allowed to return to light sports activities as early as the 8th week if the Cybex strength scores of the involved extremity exceeded 70% of the scores of the noninvolved extremity and the patient had completed a sport-specific functional/agility program. The patient database was compiled from frequent clinical examinations, periodic knee questionnaires, and objective information, such as range of motion measurements, KT-1000 values, and Cybex strength scores. A series of graft biopsies obtained at various times have revealed no adverse histologic reaction. The evidence indicates that in this population, the accelerated rehabilitation program has been more effective than our initial program in reducing limitations of motion (particularly knee extension) and loss of strength while maintaining stability and preventing anterior knee pain. J Orthop Sports Phys Ther 1992;15(6):256-264.     

Isolated anterior cruciate ligament reconstruction in the chronic ACL-deficient knee with degenerative medial arthrosis

Isolated anterior cruciate ligament (ACL) reconstruction may provide long-term symptom relief and improved function in patients with medial knee arthrosis and ACL-deficiency, while delaying or possibly eliminating the need for further surgical intervention. Fifty-three patients who had medial unicompartmental arthrosis and chronic ACL-deficient knees underwent ACL reconstruction alone. Subjective evaluation at mean 10 years postoperatively indicated statistically significant improvement compared to preoperative evaluation and better scores for patients who obtained normal knee range of motion. Objective evaluation, performed for 33 patients at a mean of 5.5 years postoperatively, indicated 25 normal or nearly normal International Knee Documentation Committee ratings; 2 patients have undergone subsequent osteotomy or total knee arthroplasty. Isolated ACL reconstruction provides long-term symptomatic pain relief, increased activity, and improved function. Anterior cruciate ligament reconstruction can effectively provide stability to the ACL-deficient knee with degenerative medial arthrosis without compromising range of motion or strength. Obtaining and maintaining full range of motion equal to the normal knee is important for the optimal result.     

The effect of injury chronicity and progressive rehabilitation on single-incision arthroscopic anterior cruciate ligament reconstruction

We conducted a prospective study on 50 consecutive patients who received a single-incision arthroscopic patellar tendon autograft reconstruction for anterior cruciate ligament (ACL) rupture. The purposes were to determine if differences existed in results between patients with acute and chronic ACL ruptures, and if a progressive rehabilitation program could safely return patients to sports activities early without compromising knee stability. Forty-two patients (84%) returned for follow-up a mean of 31 months postoperatively. Twenty-one patients had acute ruptures, and 21, chronic ruptures. A progressive rehabilitation program was used by 28 patients (67%) who met strict criteria, which allowed early return to running and sports activities. The results were rated with the Cincinnati Knee Rating System. We found no effect of either injury chronicity or time to return to activity for 21 factors, including anterior-posterior displacement, patellofemoral crepitus, range of knee motion, quadriceps muscle strength, symptoms, functional limitations, or the patient rating of outcome. Using arthrometer and pivot-shift test data, 30 knees (71%) had a functional reconstruction; 8 knees (19%) had partial function; and 4 knees (10%) failed. Patients expressed satisfaction with the operation as follows: 23 (55%) rated their overall knee condition as normal; 16 (38%), very good; and 3 (7%), good. No patients rated their knee condition as fair or poor.Arthroscopy 1998 Jan-Feb;14(1):15-22     

Anterior cruciate ligament reconstruction stability with continuous passive motion. The role of isometric graft placement.

A comparison was made of the stability of isometric versus nonisometric anterior cruciate ligament (ACL) reconstructions when subjected to immediate postoperative continuous passive motion (CPM). Anterior cruciate ligament reconstructions were performed on 13 anatomic specimen knees using bone/patellar tendon/bone grafts. Nine ACL substitutions were considered isometric with maximum graft length changes of less than 1 mm. Four ACL substitutions were nonisometric with graft length changes of 3 mm or greater resulting from tightening in flexion. The specimens were subjected to CPM through 0 degrees-95 degrees knee flexion. Knee stability was remeasured with a knee arthrometer at three and 14 days after beginning CPM. All four nonisometric specimens had failed within three days, with increased anterior laxity of 2-9 mm in both the Lachman (20 degrees) and anterior drawer (90 degrees) positions. All nine isometric reconstructions successfully retained pre-CPM anterior stability within 1 mm after 14 days of CPM. This investigation illustrates the importance of isometric graft placement for ACL reconstruction success. Continuous passive motion does not appear to adversely affect immediate ACL-substitute integrity or fixation if graft placement is isometric (less than 1 mm of graft excursion through 0 degrees-110 degrees of knee motion). Continuous passive motion may cause graft deformation, fixation failure, or both, with resultant loss of knee stability if the graft is not isometrically positioned (greater than 3 mm of graft excursion resulting from tightening in flexion).     

Arthroscopic treatment of flexion deformity after ACL reconstruction

After anterior cruciate ligament (ACL) reconstruction, one frequent complication is the restriction of the range of motion and loss of extension. In addition to the presence of adhesions in the suprapatellar pouch, it is possible to detect two different pathological findings in the intercondylar notch: a misplacement of graft causing an intercondylar impingement, or the presence of hypertrophic tissue originating from the graft that blocks the last degrees of extension, causing an "anterior impingement." We reviewed 18 consecutive cases treated by arthroscopic release. All patients had knee range-of-motion restriction after an ACL procedure. The follow-up at 1 and at 6 months shows that good results have been obtained in cases of anterior impingement, whereas in cases of intercondylar impingement a restricted range of motion, especially of flexion, did remain. In all cases, after arthroscopic treatment the postoperative extension was between 5 and 10 degrees, but this deficit regressed after 6 months in 12 patients, whereas a dropout case was necessary in the remaining 6 patients.     

Functional medical ligament balancing in total knee arthroplasty

Function of the anterior and posterior oblique portions of the medial collateral ligament and the posterior capsule in flexion and extension was evaluated in eight knee specimens after posterior cruciate retaining total knee arthroplasty. The posterior oblique portion of the medial collateral ligament was released subperiosteally in four specimens, and the anterior portion was released in four specimens. The medial posterior capsule was released in each group, then the remaining portion of the medial collateral ligament was released. Release of the posterior oblique portion produced moderate laxity at full extension and at 30 degrees flexion, and posterior capsule release produced additional laxity in full extension. Release of the anterior portion produced major laxity at 60 degrees and 90 degrees flexion. Complete medial collateral ligament release increased laxity significantly in both groups in flexion and extension. This rationale was tested in a clinical study of 82 knees (76 patients) in which 62 (76%) required medial collateral ligament release to correct varus deformity during posterior cruciate retaining total knee arthroplasty. Twenty-two knees (35.5%) were tight medially in extension only, and were corrected by releasing the posterior oblique portion. Thirty-one knees (50%) were tight medially in flexion only, and were corrected by releasing the anterior portion. Nine knees (14.5%) were tight medially in flexion and extension and required complete medial collateral ligament release, but three knees (4.8%) remained tight in extension and required medial posterior capsule release to correct flexion contracture and medial ligament contracture. Seventeen (27%) had partial posterior cruciate ligament release to correct excessive rollback of the femoral component on the tibial surface.     

Septic arthritis in postoperative anterior cruciate ligament reconstruction

A review of postoperative infected anterior cruciate ligament reconstructions was done on 3500 consecutive arthroscopic procedures. The purpose was to assess incidence, diagnosis, treatment, and outcome factors. Six postoperative intraarticular infections were detected. Average followup was 3 years (range, 2-8 years). The rate of infection was 0.14%. Five men and one woman with a median age of 32.5 years (range, 20-51 years) comprised the study group. The average interval from the onset of symptoms to the initial arthroscopic intervention was 7.5 days (range, 2-20 days). Staphylococcus aureus was present in three knees, Staphylococcus epidermidis in two, and Streptococcus nonhemolytic in one. All patients had initial arthroscopic debridement and lavage followed by 6 weeks of intravenous antibiotics. Two grafts were removed: one patient had delayed ligament reconstruction and the other had total knee arthroplasty. The remaining patients had full range of motion. In the group with the best result, two patients had Staphylococcus epidermidis and one had Staphylococcus aureus, which was treated 2 days after clinical symptoms began. The other two patients infected with Staphylococcus aureus had unsatisfactory results. Anterior cruciate ligament infection is rare, but diagnosable. When treated early with appropriate antibiotic therapy and arthroscopic debridement, four of six grafts were retained. If the infection does not respond rapidly to early therapy, then graft removal is an option.     

Rationale and protocol for postoperative anterior cruciate ligament rehabilitation

A rehabilitation program for postoperative anterior cruciate ligament (ACL) reconstruction permits adequate tissue healing time and allows early protected muscular conditioning. The program is based on kinematic, biomechanical, and kinesiologic factors as they pertain to ACL function. The program is divided into five phases. The early phases, zero to 12 weeks, are intended to control translational forces across the ACL and to allow necessary time for ligament revascularization and soft-tissue healing. During this period, isometric and isotonic training of the hamstrings and quadriceps muscle groups in a restricted active arc of motion is permitted. Passive motion is encouraged, and progressive weight bearing is allowed. Conditioning of the upper body as well as the nonsurgical lower limb is stressed. During the advanced phases, 12-31 weeks, isotonic muscle training continues throughout a full range of motion. Greater strength, coordination, and endurance to achieve dynamic stability of the knee, preparing the patient for unrestricted activity, are stressed. Approximately 52 weeks of active rehabilitation after ACL reconstruction surgery are usually required to return to a preinjury level of function.     

Case series utilizing drop-out casting for the treatment of knee joint extension motion loss following anterior cruciate ligament reconstruction

STUDY DESIGN: Case series. CASE DESCRIPTION: Four patients who had developed knee extension motion loss following anterior cruciate ligament reconstruction were referred to physical therapy for treatment. They were treated with drop-out casting and completed a Lower Extremity Functional Scale at baseline, at the time of application of the drop-out casting, and at discharge. OUTCOMES: Three males and 1 female with a mean age of 20.5 years (range, 18-22 years) were referred to physical therapy a mean of 31 days (range, 19-49 days) following bone-patella tendon-bone autograft anterior cruciate ligament reconstruction. The mean number of physical therapy sessions attended was 29.5 visits (range, 20-47 visits). The mean improvement in knee extension range of motion (ROM) and knee flexion ROM prior to the application of drop-out casting was 4.3 degrees (range, -1 degree to 10 degrees) and 24.3 degrees (range, 0 degree to 40 degrees), respectively. The mean improvement on the Lower Extremity Functional Scale was 10.3 points prior to drop-out casting. At time of discharge, the total mean improvement in knee extension ROM loss was 11.0 degrees (range, 4 degrees to 15 degrees), knee flexion ROM was 30.8 degrees (range, 22 degrees to 35 degrees), and Lower Extremity Functional Scale was 12 points (range, -5 to 21 points). Two of the patients were able to complete a running program without difficulty, while the other 2 patients had difficulty with higher-level activities. DISCUSSION: Despite the low incidence of knee extension ROM loss following surgery, the inability to achieve full knee extension does occur and can have debilitating consequences. When early emphasis of full passive knee extension has been inadequate, these results suggest that improving knee extension motion without inhibiting knee flexion motion is possible with the use of a drop-out cast. Future research should focus on comparison of drop-out casting to dynamic splinting, as well as the optimal frequency and duration of low-load long-duration stretching using a drop-out cast.     

Revision anterior cruciate ligament reconstruction using the lateral third of the ipsilateral patellar tendon after failure of a central-third graft: a preliminary report on 10 patients

Long-term outcomes were reported for 10 (77%) of 13 cases of revision anterior cruciate ligament (ACL) reconstruction using the lateral third of the ipsilateral patellar tendon as a graft. All primary ACL reconstructions were ipsilateral central-third bone-patellar tendon-bone graft procedures. Mean age at follow-up was 30.7 years, and mean time from revision ACL surgery to follow-up was 42.9 months. At follow-up, average KT-1000 difference between knees was 2.4 mm. All patients had a negative pivot shift, extension within 5 degrees of the contralateral knee, and flexion within 15 degrees. Mean bilateral comparison ratios for isokinetic strength and hop testing were: extension, 83.5%; flexion, 96%; and single-leg hop 96.9%. No patella fractures or tendon ruptures had occurred. All patients had returned to their previous work level, and 8 of the 10 patients could participate in at least "moderate" sports activities (e.g., skiing and tennis). The results were comparable to published outcome reports for both primary and revision ACL reconstruction. The lateral third of the ipsilateral patellar tendon is a good graft option for revision ACL reconstruction.     

A synovial osteochondroma replacing the anterior cruciate ligament at the intercondylar notch

A woman presented with knee pain and locking. Pain was exacerbated at the end of the range of motion, especially during extension, with locking symptoms similar to those associated with a meniscus bucket handle tear. Ligamentous laxity was not definite. Plain radiographs showed multiple calcified loose bodies. Magnetic resonance imaging (MRI) showed a lobulated mass that was hypointense to muscle on T1-weighted sequences and hyperintense to muscle on T2-weighted sequences in the anterior cruciate ligament (ACL). Arthroscopically, multiple loose bodies were observed in the intercondylar notch and posterolateral compartment. A huge mass replaced the normal ACL and was caught in the intercondylar notch. The mass in the intercondylar notch caused loss of extension range of motion (ROM) because the piece caused a mechanical blockage. However, the loss of flexion ROM was likely caused by a loss of elasticity of the ligament rather than mechanical blockage. We resected the ACL mass, and removed the free bodies from the posterolateral corner. It was not possible to preserve the ACL fibers. Histological examination confirmed a diagnosis of osteochondromatosis. All symptoms resolved postoperatively. At 20 months postoperatively, the patient was pain free and had regained full knee motion without recurrence evidenced by follow-up MRI. However, ACL removal caused the knee instability. To date the patient has not undergone ACL reconstruction because she prefers conservative treatment and has experienced little discomfort in activities of daily living. To our knowledge, this is the first report to describe synovial osteochondromatosis wholly replacing the ACL fibers and causing mechanical blocking of both extension and flexion.