Acute extension block caused by anterior cruciate ligament tear: A case report

Acute knee locking is usually attributed to a displaced meniscus tear. This case involved late diagnosis of mechanical extension block caused by anterior displacement of a torn anterior cruciate ligament (ACL) with impingement in extension. Definitive reconstruction was delayed after debridement of the ACL stump to improve preoperative range of motion. Despite this, the patient still had difficulty regaining extension after surgery. Early treatment of mechanical extension block may facilitate motion recovery after ACL reconstruction.     

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 early treatment of motion complications after reconstruction of the anterior cruciate ligament.

The use of active and passive knee motion in the immediate postoperative period and a treatment plan for early postoperative limitations in knee motion has proven highly effective in restoring motion after anterior cruciate ligament (ACL) reconstruction. Of 207 knees, 189 (91%) regained a full range of motion of 0 degrees-135 degrees. The remaining 18 knees (9%) did not regain motion as rapidly as the others and were placed in an early postoperative phased treatment program. Six knees had serial extension casts, nine had early gentle manipulation under anesthesia, and three had arthroscopic lysis of intraarticular adhesions and scar tissue. Fourteen of these 18 knees regained a full range of knee motion. Two of the remaining four knees lacked 5 degrees of full extension, whereas the other two, in patients who had failed to follow medical advice and the rehabilitation program, had permanent and significant limitation of motion. The incidence of postoperative motion problems was related to the extent of the surgical procedure. The incidence was 4% in patients who had only ACL reconstruction, 10% in cases in which added lateral extraarticular procedure had been done, 12% where a meniscus repair had been done, and 23% where a medial collateral ligament repair was done.     

Arthroscopic protocol for treatment of knee extension block after patellar ACL reconstruction

This study presents a new protocol for arthroscopic approach based on the treatment of 36 patients with extension block of the knee as a result of intra-articular reconstruction of the anterior cruciate ligament (ACL) using the patellar tendon. Arthroscopy not only allowed the identification of the active mechanical extension block of the knee, but also the passive mechanical block that can occur with a functional or loose ligament. This protocol can be useful in the treatment of postoperative extension block of the knee as a complication of 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.     

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.     

Central third bone-patellar tendon-bone arthroscopic anterior cruciate ligament reconstruction: a 4-year follow-up

This prospective study reports the 4-year follow-up results of 56 patients (44 males and 12 females) who underwent arthroscopic reconstruction of the anterior cruciate ligament (ACL) using a central third bone-patellar tendon-bone free autologous graft and assesses the mid-term effectiveness of this technique. Mean patient age was 30.2 years (range: 17-44 years). Sports injuries were the primary cause of ACL deficiency in 93% of patients. All knees had an isolated ACL tear, and 31 had associated meniscal or chondral lesions. Patients in the acute phase did not undergo surgery for 3-4 weeks. In patients with subacute and chronic ACL ruptures, the mean interval between injury and surgery was 62 weeks (range: 8-104 weeks). According to the International Knee Documentation Committee grading system, 53 (95%) knees were considered normal or nearly normal postoperatively. Improvement by at least 1 grade was noted in 12 knees, 30 knees had an improvement of at least 2 grades, 12 knees had a 3-grade improvement, and 1 had a grade that remained unchanged. One knee deteriorated from a grade C to a grade D, which was attributed to graft lysis 1 year postoperatively. For best results, subacute reconstruction between 3 and 5 weeks postinjury is recommended.     

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.     

Effects of knee flexion angle at graft fixation on the outcome of anterior cruciate ligament reconstruction

Clinical outcome in 44 patients who underwent anterior cruciate ligament (ACL) reconstruction with hamstring tendons augmented by the ligament augmentation device for chronic ACL deficiency was studied; average follow-up was 38 months (range, 24 to 52 months). In 19 patients, grafts were fixed with the knees at full extension (group 1), whereas in 25 patients, the grafts were fixed with the knees at 30° of flexion (group 2). The results of subjective testing (Lysholm score), the Lachman test, the pivot-shift test, muscle strength testing, angle of extension loss, and follow-up arthroscopy were compared to assess the effects of flexion angle at fixation on stability and function. The range of motion in group 1 was significantly better than that in group 2. The stability of the knees and the arthroscopic appearance of the grafts in group 1 were, however, significantly worse than those in Group 2.     

Intraarticular fibrous nodule as a cause of loss of extension following anterior cruciate ligament reconstruction.

Loss of motion is a well-known complication following anterior cruciate ligament (ACL) reconstruction. We have found that loss of extension is more disabling than loss of flexion, and is a more common problem following arthroscopic assisted ACL reconstruction. We are reporting on a group of 21 patients who have developed restricted knee extension following ACL reconstruction utilizing either the central one-third of the patellar ligament or the hamstring tendons as an autogenous graft. The patients presented at an average of 4 months postoperatively with a clinical syndrome of loss of extension associated with pain at terminal extension, crepitus, and grinding with attempted extension beyond their limit. The consistent finding at arthroscopy was a fibrous nodule occupying the intercondylar notch, varying in size from 1 x 1 to 2 x 3 cm, and presenting a mechanical block to full extension. It appears that anterior placement of the graft, particularly on the tibia, results in injury to the graft and subsequent nodule formation. Removal of the nodule resulted in improvement of an average preoperative loss of extension of 11 degrees, to 3 degrees at surgery, and 0 degrees at 1 year follow-up. The average side-to-side difference in terminal extension at final examination, using the uninvolved limb for comparison, was 3 degrees. Histology was available for review on 19 of the 21 patients operated on. The consistent microscopic finding within the nodule was the presence of disorganized dense fibroconnective tissue that, with time, underwent modulation to fibrocartilage. It is postulated that this occurs in response to compressive loading of the nodule.     

The effect of anterior cruciate ligament reconstruction on symptoms of pain and instability in patients who have previously undergone meniscectomy: A prereconstruction and postreconstruction comparison

To determine the effect of anterior cruciate ligament (ACL) reconstruction on symptoms of pain and instability in patients with chronic ACL insufficiency who had previously undergone meniscectomy, we reviewed a series of 21 symptomatic, previously meniscectomized patients with chronic ACL deficiency (average age, 31 years). Arthroscopically assisted intra-articular ACL reconstruction using a middle, one-third patella-tendon autograft was performed in all cases. All patients had radiographic evidence of degenerative changes before ACL reconstruction. The average time from meniscectomy to ACL reconstruction was 6.6 years. Preoperative and postoperative range of motion, stability, and subjective evaluations were compared. Follow-up averaged 37.4 months (range, 24 to 67 months). Physical examination and postoperative KT-1000 side-to-side measurements revealed three patients (14%) with pathological ligament laxity. One patient had a 2+ Lachman, a 2− pivot shift, and >5 mm difference on KT-1000 maximum manual test, and two patients had a 1+ Lachman and a 1+ pivot shift. Range of motion measurements taken at follow-up were not significantly different from preoperative measurements (extension, P = .14; flexion, P = .46). Subjectively, all items on a panel of 15 visual analog scales were improved, but intensity of pain and instability were significantly improved after statistical analysis (P < .05). This review suggests that symptoms of pain and instability in patients with chronic ACL deficiency who have previously undergone meniscectomy can be improved by ACL reconstruction if objective stability is obtained.     

Decreased range of motion following acute versus chronic anterior cruciate ligament reconstruction

Eighty patients with acute anterior cruciate ligament (ACL) reconstruction were compared to 80 patients with chronic ACL reconstruction. Before reconstruction, all patients had 0 degrees-120 degrees active motion, performed a straight leg raise without loss of extension, and demonstrated good quadriceps control. At 3 months, 4 acute patients had decreased range of motion (<10 degrees-120 degrees), but none at 6 or 12 months, and did not require repeat surgery. One chronic patient had decreased range of motion at 3 and 6 months and 1 patient had decreased range of motion at 1 year; both patients required operative intervention. Using these specific preoperative criteria, no increased incidence of decreased range of motion was found when an ACL reconstruction was performed within 3 weeks of injury.     

Dynamic external fixation for comminuted intra-articular fractures of the distal end of the radius

An external fixation device that allows motion of the wrist was developed for the treatment of severely comminuted intra-articular fractures of the distal end of the radius, and in specimens from cadavera that motion was demonstrated with the device in place. Thirty patients who had thirty-two comminuted intra-articular radial fractures were then treated with fixation using this device during a six-month interval. Thirty-one of the wrists were examined at follow-up one and two years later. The first fifteen wrists that were allowed full flexion and extension immediately postoperatively had lost some volar tilt postoperatively. The other patients, for whom only flexion was allowed immediately postoperatively, while extension was allowed four weeks later, did not lose volar tilt. The device maintained the reduction of the fracture fragments and allowed the early return of a functional range of motion of the wrist.     

Spontaneous healing of acute anterior cruciate ligament (ACL) injuries - conservative treatment using an extension block soft brace without anterior stabilization

To evaluate the spontaneous healing capability of acute anterior cruciate ligament (ACL) injuries, conservative treatment was applied in a selected group of 31 patients, who had low athletic demands. Each patient demonstrated a continuous ACL on magnetic resonance imaging (MRI), from the original femoral attachment through the tibial attachment, and an area of high intensity was detected in the substance of the ACL. The injured knees were treated using an extension block soft brace without anterior stabilization for 2-3 months. KT-2000 and MRI examinations were carried out regularly during the follow-up. Twenty-three knees (74%) were revealed to be stable in the follow-up examination, with an average of 16.1 months elapsing since the initial injuries. The KT-2000 side-to-side differences of 20 knees were less than 3 mm, and those of the other 3 knees were more than 3 mm but less than 5 mm. MRI confirmed that 21 injured ACL out of 23 knees maintained a femoral to tibial attachment and showed gradual reductions in image intensity. The positions of the other 2 injured ACL femoral attachments were different from the original femoral attachment: one was attached to the posterior cruciate ligament, and the other was located at the lateral femoral condyle anterior to the original femoral attachment. Eight knees (26%) subsequently required ACL reconstructions due to instability. This study indicates that an acutely injured ACL has healing capability. It also suggests that conservative management of the acute ACL injury can yield satisfactory results in a group of individuals who have low athletic demands and continuous ACL on MRI, provided the patients are willing to accept the slight risk of late ACL reconstruction and meniscal injury.     

The gross morphology of torn human anterior cruciate ligaments in unstable knees.

To evaluate the presence and incidence of reattachments of torn human anterior cruciate ligaments (ACL), we prospectively investigated 101 patients undergoing arthroscopic ACL reconstruction to study the intra-articular morphology of ACLs under circumstances in which functional healing had failed. Results showed that roughly 72% of these unstable knees had reattachment of the torn ACL to the posterior cruciate ligament (PCL). Eighteen percent had no signs of ACL reattachment but only 2% of previously torn ACLs were absent. These results suggest that even in chronic situations in which the knee remains functionally unstable, human ACLs rarely resorb. It also suggests that torn human ACLs commonly reattach in the knee, mainly to the PCL via a process that is consistent with scarring. While the function of these reattachments is clearly inadequate in people with unstable knees because of a combination of reattachment location, scar quantity, or quality, these results nonetheless show that the intra-articular environment in humans often maintains ACL stumps and it is not totally inhibitory to ACL reattachment via some biological process.     

Proprioception of the knee before and after anterior cruciate ligament reconstruction

Purpose: The purpose of this study was to determine, first, if there is measurable deficit in proprioception in an anterior cruciate ligament (ACL)-deficient knee, either compared to the contralateral knee or external controls; second, if this deficit, if present, improves after ACL reconstruction; and third, if improvement occurs, what the time course of improvement is. Type of Study: Prospective cohort study. Methods: Patients undergoing ACL reconstruction at the University of Chicago, demonstrating a full and painless range of motion and no other knee ligament injury or history of previous knee surgery, were eligible. Twenty-six patients, with an average age of 25 years (range, 16 to 48) were enrolled. Average time from injury to reconstruction was 8 weeks. The patients' contralateral knee served as an internal control, and 26 age-matched and gender-matched healthy volunteers were enrolled as an external control group. ACL reconstructions were performed using a single-incision technique with either bone–patellar tendon–bone or quadrupled hamstring autograft. They were allowed immediate weightbearing as tolerated and participated in a standardized rehabilitation program, with the goal of returning to sport at approximately 6 months. Proprioception testing was carried out using an electrogoniometer, in a seated position. Joint position sense (JPS) and threshold to detection of passive motion (TDPM) were measured preoperatively and at 3 and 6 weeks and 3 and 6 months postoperatively. Results: Mean KT-2000 values 6 months postoperatively were 1.38 mm (±2). Modified Lysholm score improved significantly (P < .01). Calculated r values were 0.65 for JPS and 0.96 for TDPM. No significant differences in postoperative proprioception were found between hamstring and patellar tendon grafts or among patients with meniscus injury, meniscus repair, or chondral injury. Preoperatively, the mean TDPM in both the injured and contralateral knees was significantly higher (worse) than in the external control knees (P = .008; P = .016). Evaluation of changes in proprioception from preoperative to 6 months postoperative showed significant improvement in both injured and contralateral knees (P = .04; P = .01). At 6-month follow-up, there was no significant difference from controls. Conclusions: TDPM was a more reliable method than JPS for testing proprioception before and after ACL reconstruction in this study. Bilateral deficits in knee joint proprioception (TDPM) were documented after unilateral ACL injury. Reconstruction of a mechanical restraint (ACL graft) was believed to have a significantly positive impact on early and progressive improvement in proprioception.     

Anterior cruciate ligament reconstruction and physiological joint laxity: earliest changes in joint stability and stiffness after reconstruction

Physiological joint laxity is an important element of normal knee joint function, providing smooth joint movement. However, the objective evaluation of post-operative results after knee ligament surgery is usually based primarily on stability and range of motion, and joint laxity has been ignored. In this study, we measured the joint stiffness of 82 knees undergoing anterior cruciate ligament (ACL) reconstruction with the Leeds-Keio artificial ligament, before the operation, immediately after the operation, and finally when the full range of motion was achieved postoperatively; changes in joint laxity after the ACL reconstruction were investigated. Before the operation, joint laxity was greater than that of the normal side (P < 0.01), but immediately after the operation it diminished compared not only with that observed preoperatively, but also with that of the normal side. When the full range of motion was achieved, joint laxity was lower than that observed immediately after the operation (P < 0.01), but still remained higher than that of the normal side (P < 0.01). In other words, stability was achieved, but joint laxity was diminished through the operation. In this series, a stiffer artificial ligament than the natural ACL was used, and maximum tension was applied during the operation, aiming at better stability, but this may cause diminution of joint laxity. Received for publication on Sept. 1998; accepted on Dec. 2, 1998     

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.     

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     

Definitive landmarks for reproducible tibial tunnel placement in anterior cruciate ligament reconstruction

The purpose of this prospective study was to define constant anatomic intraarticular and extraarticular landmarks that can be used as definative reference points to reproducibly create a tibial tunnel for anterior cruciate ligament (ACL) reconstruction that (1) results in an impingement-free graft in full extension without an intercondylar roofplasty; (2) positions the tibial tunnel's intraarticular orafice sagittally central in the original ACL insertion without visually guessing; (3) positions the tibial tunnel such that the sagittal tunnel-plateau angle is parallel with the sagittal intercondylar roof-plateau angle in full extension to minimize shear seen by the graft at the tibial tunnel inlet, and by doing so; (4) maximizes tunnel length to avoid patellar tendon graft-tunnel length mismatch allowing for endosteal interference screw fixation on both sides of the joint. Anatomic dissections in 50 knees showed the ACL sagittal central insertion point on the intercondylar floor averages 7 mm (range 7 to 8 mm) sagittally anterior to the anterior margin of the posterior cruciate ligament (PCL) with the knee flexed 90° such that the PCL may be used as a reliable reference landmark for locating the ACL sagittal central insertion. This constant relationship was found to be independent of knee size. Extraarticularly, beginning the tibial tunnel sagittally 1 cm above the superior (sartorial) border of the pes anserinus insertion and coronally 1.5 cm posteromedial from the medial margin of the tibial tubercle along the superior surface of the pes, directed toward the sagittal central ACL insertion, led to a sagittal tunnel-plateau angle that averaged 68°(range 64° to 72°) with a corresponding tunnel length that averaged 58 mm (range 50 to 65 mm) in 23 knees. This data correlated well with data obtained clinically in a series of 50 consecutive ACL reconstructions using intraarticular PCL and extraarticular pes anserine-medial tibial tubercle referenced tibial tunnels in which postoperative full extension lateral radiographs confirmed a sagittal tunnel-plateau angle parallel or near parallel with the intercondylar roofplateau angle in all cases averaging 68° ± 3.8°. Tibial tunnel length averaged 60 mm (range 52 to 66 mm) and in no case was there a patellar tendon autograft-tunnel length mismatch.