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

Single-incision endoscopic anterior cruciate ligament reconstruction using patellar tendon autograft. Minimum two-year follow-up evaluation

We conducted a retrospective, minimum 2-year follow-up study to evaluate the effectiveness of a single-incision endoscopic anterior cruciate ligament reconstruction technique using patellar tendon autograft without extraarticular augmentation and followed by accelerated rehabilitation. One hundred three patients were evaluated (mean followup, 36 months; range, 24 to 55). There were significant improvements in physical examination test results (Lachman, anterior drawer, and pivot shift) postoperatively, and 94 patients (91%) had negative pivot shift results. KT-1000 arthrometric testing showed a significant reduction in manual maximum anterior translation and side-to-side differences at followup. Good range of motion was achieved. Patients with asymmetric prone heel heights usually had hyperextension in the contralateral knee. Functional tests showed 4% to 6% differences in side-to-side comparisons for a timed single-legged hop, single-legged hop for distance, and vertical jump. Postoperatively, the results of the Tegner scale were similar to preinjury scores. The mean results of the Hospital for Special Surgery scale (90), Lysholm score (89), and Noyes sport function score (90) were all excellent or good. Only 5 patients (5%) required reoperations for flexion contractures. Ninety-six patients (93%) reported they were "mostly" or "completely" satisfied, and 98 (95%) would recommend the procedure to others. These results demonstrated encouraging outcome using this single-incision technique.

Arthroscopic anterior cruciate ligament reconstruction using autogenous hamstring tendon graft without detachment of the tibial insertion

This article describes a modified arthroscopic technique of anterior cruciate ligament reconstruction using quadrupled hamstring tendon graft. The autogenous semitendinosus and gracilis grafts are harvested without detachment of the tibial insertion. To obtain longer grafts, the accessory tibial insertions of the hamstring tendons are dissected. The EndoButton (Acufex Microsurgical, Andover, MA) is used for femoral fixation and two spiked staples are used for tibial fixation in a belt buckle fashion. Then the residual anterior laxity is restored by additional absorbable interference screw fixations. In this technique, more viable graft is obtained and more firm distal fixation is achieved by preservation of the tibial insertion of hamstring tendons.

Anterior cruciate ligament graft fixation. Initial comparison of patellar tendon and semitendinosus autografts in young fresh cadavers

The initial biomechanical properties of semitendinosus and patellar tendon autografts and their fixation strengths were investigated. Twenty fresh cadaveric knees from donors under 42 years of age were used in the study. After removing all soft tissues other than the anterior cruciate ligament, we determined the ultimate tensile strength (2195 +/- 427 N) and stiffness (306 +/- 80 N/mm) of the anterior cruciate ligament in nine knees. In six knees, anterior cruciate ligaments were reconstructed using an autologous patellar tendon graft with proximal and distal interference fit screws; this resulted in an ultimate tensile strength of 416 +/- 66 N. Five knees were reconstructed with quadruple-stranded (double-looped) semitendinosus tendons fixed proximally by a titanium button and braided tape and distally by tibial post screw. This resulted in an ultimate tensile strength of 612 +/- 73 N, which was significantly higher than the strength in the patellar tendon group. Graft stiffness did not differ between the groups and was 47 +/- 19 N/mm (N = 11). This study demonstrates that the reconstructed knees had only 20% to 30% of the ultimate tensile strength of the normal anterior cruciate ligament. In summary, the semitendinosus reconstruction using a button for proximal fixation is, at the time of surgery, approximately 50% stronger than patellar tendon reconstructions with similar stiffness.

A prospective, clinical study evaluating arthroscopic ACL reconstruction using the semitendinosus and iliotibial band: 2- to 5-year follow up

Seventy-three ACL-deficient knees were reconstructed using a modified Zarins and Rowe arthroscopic procedure utilizing the semitendinosus tendon and iliotibial band (ITB). Fifty of 73 patients returned for 2- to 5-year follow up. On follow-up visit each patient completed a questionnaire pertaining to subjective results, including level of pain and return to, activities. Physical examination included the Lachman test, anterior drawer, pivot shift, and anterior subluxation tests (using the Stryker KT 1000), each graded 0 to 3. All patients have shown a statistically significant improvement between preoperative and postoperative knee scores (P < .0001). According to the knee scoring scale, 34 patients (68%) were clinically rated as excellent, 12 (24%) as good, 4 (8%) as fair, with no poor results. All patients have returned to pre-injury jobs (or school), while most resumed some level of sporting activities. No patients complained of patella femoral symptoms postoperatively. Complications included pain over the staple which was used for fixing the ITB to the tibia, requiring removal in 5 patients. These preliminary results are encouraging, with 92% of the patients rating good to excellent. This modified procedure offers advantages over other procedures, as it is entirely arthroscopic with minimal incisions, does not damage the extensor mechanism, and permits an enhanced rehabilitation program.

Preventing anterior knee pain after anterior cruciate ligament reconstruction

We studied a group of 602 patients who had anterior cruciate ligament reconstructions between 1987 and 1992. An autogenous patellar tendon graft was used, regardless of preexisting patellofemoral pain or chondromalacia. The surgeon and rehabilitation protocol were the same for all patients, with emphasis on obtaining full knee hyperextension postoperatively. All patients were evaluated by a questionnaire designed to determine the incidence and severity of anterior knee pain as it relates to sporting or daily living activities, prolonged sitting, stair climbing, and kneeling. Range of motion for the study group was recorded during physical examination. We compared the findings with those from a control group of 122 patients who had no previous knee injury. The study group reported a mean score of 89.5 +/- 12.5, compared with 90.2 +/- 12.3 in the control group. Both the operative and control groups reported little or no symptoms during sporting activities (94% and 92%, respectively). No differences were noted with respect to the other activities surveyed. These results demonstrate that anterior knee pain after anterior cruciate ligament reconstruction is not an inherent complication associated with patellar tendon harvesting. We suggest that the increased incidence of anterior knee pain with an autogenous patellar tendon graft can be prevented by obtaining full knee hyperextension postoperatively. This goal can be achieved through preoperative rehabilitation and a postoperative protocol emphasizing early restoration of full knee hyperextension.

Arthroscopic posterior cruciate ligament reconstruction using hamstring tendons: one-incision technique with Endobutton

The one-incision surgical technique using autogenous hamstring tendons with Endobutton (Acufex Microsurgical Inc. Mansfield, MA) femoral end fixation for posterior cruciate ligament reconstruction is described. This technique avoids a second incision on the femoral side, and is adaptable to various graft materials (autogenous or allogeneic bone-patellar tendon-bone, hamstring, or Achilles tendon.

Late patellar tendon ruptures after removal of the central third for anterior cruciate ligament reconstruction. A report of two cases

Patellar tendon rupture after removal of the central third for ACL reconstruction is a rare complication. Only nine cases have been previously reported, and all of these occurred within the first 10 months after surgery. We report two cases of late patellar tendon ruptures occurring at more than 3 and 6 years, respectively, after surgery. A review of the literature has suggested but not conclusively supported that devascularization, an alteration in tendon healing and remodeling, or injury to the remaining tendon at the time of graft harvest may be possible causes of this rare complication. Biopsy tissue from any future patellar tendon ruptures after removal of its central third could contribute to a better understanding of this anomaly.

Comparison of anterior cruciate ligament reconstructions using patellar tendon autograft or allograft

Seventy-eight of 113 consecutive patellar tendon anterior cruciate ligament reconstructions (autograft, 47 of 66; allograft, 31 of 47) were evaluated at an average of 34 months. Reconstructions were compared with Lysholm and Tegner knee-rating scales, physical examination findings, instrumented laxity values, single-leg hop distances, and isokinetic strength results. Lysholm scores > or = 90 were achieved by 69% of autograft patients versus 67% of allograft patients. Desired Tegner activity scores were achieved by 80% of autograft patients versus 74% of allograft patients. Patellofemoral signs and symptoms were absent in 40% of autograft patients versus 44% of allograft patients. Side-to-side laxity differences < or = 3 mm were achieved in 80% of autograft patients versus 70% of allograft patients. Single-leg hop scores > or = 90% of the nonoperated leg were obtained in 76% of autograft patients versus 81% of allograft patients. Isokinetic results between groups were also similar. Traumatic ruptures were sustained by four allograft patients at an average of 11 months postoperatively compared with no traumatic ruptures in the autograft group (P = .011). This was the only difference of statistical significance.

Anterior cruciate ligament reconstruction with multistranded autogenous semitendinosus tendon

We evaluated 41 knees 24 to 48 months after anterior cruciate ligament reconstruction was performed using multiple autogenous semitendinosus tendons. The ipsilateral free semitendinosus tendon was tripled or quadrupled to make a graft 7 to 10 mm in diameter and more than 60 mm long. When the diameter of the graft was less than 7 mm, an ipsilateral doubled gracilis tendon was also used (in seven cases). Twenty-three patients (56%) returned to their preinjury activity levels. According to the patients' subjective assessment, 34 (83%) graded themselves as normal or nearly normal. No patient reported giving way of the knee or limitation of knee motion. The average anterior laxity difference between the involved knee and contralateral uninjured knee was 1.5 mm at 200 N. Twenty-nine patients (71%) demonstrated an anterior laxity difference of 3 mm or less when the involved knee was compared with the contralateral uninjured knee. Quadriceps muscle strength was 90% compared with the contralateral healthy limb, and hamstring muscle strength was equivalent to the contralateral limb. In our study, tripled or quadrupled semitendinosus free tendons were excellent anterior cruciate ligament grafts for restoring knee stability, recovering thigh muscle power, and preserving knee motion.

A functional knee brace alters joint torque and power patterns during walking and running

Individuals with anterior cruciate ligament (ACL) injury use greater extensor torques at the hip and ankle and lower extensor torques and joint power at the knee during gait compared to healthy subjects. These adaptations may be mediated by (1) altered neuromuscular strategies due to the injury, (2) training effects produced by rehabilitation protocols, and (3) training effects due to the functional knee brace (FKB) used during rehabilitation. The purpose of the study was to test the hypothesis that a FKB can cause individuals to walk and run with the torque and power patterns observed in rehabilitated ACL-injured individuals. Ten healthy subjects were tested walking and running with and without a FKB. Kinematic and ground reaction data were collected and combined with inverse dynamics to estimate the joint torques and powers. Data were analyzed with a two-way repeated measures ANOVA (gait vs knee condition). In walking, the hip and ankle extensor torques were 14.3% (p < 0.038) and 5.1% (p < 0.003) greater with FKB. In running, the hip extensor torque was 17.0% greater with FKB (p < 0.023). Knee torque was not different between conditions. In walking, the work performed at the hip and knee were 11.6% greater (p < 0.013) and 17.7% lower with FKB (p < 0.025), respectively. Results supported the hypothesis and it was concluded that a FKB may be one causative factor in the development of the unique joint torque and power patterns seen in ACL-injured gait.

Graft selection in anterior cruciate ligament revision surgery

Revision anterior cruciate ligament surgery can be very demanding. Graft selection for revision surgery is a pivotal part of this procedure. Often, the usual first choice of tissue is not available. Therefore, familiarity with alternative graft sources and understanding their advantages and disadvantages is imperative for the surgeon who does anterior cruciate ligament revision surgery. This study will review the advantages and disadvantages of each graft choice available to the surgeon for this procedure.

Primary repair plus intra-articular iliotibial band augmentation in the treatment of an acute anterior cruciate ligament rupture. A follow-up study of 70 patients

Between September 1987 and November 1989, we treated 90 consecutive patients with an acute anterior cruciate ligament (ACL) rupture with the multiple suture technique and iliotibial band augmentation. Seventy of these patients were re-examined 2 to 5 years after the operation (mean 3.5 years), the examination consisting of a questionnaire, clinical examination, laxity tests with the KSS machine (Acufex), radiological examination and isokinetic muscle strength testing (Cybex 6000). There were 32 men and 38 women (mean age 34 years). The injury was sustained in sports in 44 (63%) cases, and the sports most frequently involved were downhill skiing (18 cases), soccer (9 cases) and volleyball (5 cases). Of the injuries, 38 were isolated ACL ruptures and 31, ACL ruptures combined with a medial CL rupture. In 9 cases, an additional meniscus injury and in one case an additional posterior CL - lateral CL rupture was found. At the follow-up, 55 patients (79%) were satisfied with the end result, and according to our objective functional criteria 55 (79%) had an excellent or good outcome. According to the Lysholm score, 53 (76%) patients were excellent or good (> or = 82 points). In the Lachman test, 29 knees (41%) were completely stable. The Lachman test was mildy positive in 40 knees (57%) (36 had 1+ laxity and 4, 2+ laxity), and one patient had 3+ laxity with a hard end-point. Similarly, the anterior drawer test was negative in 53 knees (76%), and the other 17 (24%) had mild laxity (16 had 1+ laxity and 1, 2+ laxity). The total anterior-posterior laxity measured with the KSS averaged 9.7 +/- 3.5 mm in the injured knee and 7.3 + 3.0 mm in the uninjured knee (the laxity measured at a knee angle of 20 degrees of flexion). Corresponding values at a knee angle of 90 degrees of flexion were 6.1 +/- 2.4 mm and 4.7 +/- 1.9 mm, respectively. The pivot shift test was negative in 62 patients (89%) and 1+ positive in the remaining 8 patients (11%). Fifty-eight patients (83%) had full knee extension and 40 patients (57%), full knee flexion. Compared with the uninjured knee, the operated knees showed an average 14% strength deficit in isokinetic knee extension and 6% deficit in flexion at the speed of 60 degrees/s. At the speed of 180 degrees/s, the corresponding deficits were 8% and 4%, respectively. Of the 44 patients who were active in sport before the injury, 40 (91%) were able to return to sports. A flexion deficit of 5 degrees or more was associated with thigh muscle atrophy (P < 0.05) and quadriceps weakness, both at the slow speed (P < 0.05) and high speed (P < 0.001) of the isokinetic movement. In conclusion, in an acute rupture of the ACL, primary repair of the ligament with intraarticular iliotibial band augmentation seems to be a good method to restore the functional capacity of the injured knee.

Effects of an accelerated rehabilitation program after anterior cruciate ligament reconstruction with combined semitendinosus-gracilis autograft and a ligament augmentation device

Forty patients with anterior cruciate reconstructions using semitendinosus and gracilis autografts and a ligament augmentation device were reviewed at a minimum of 20 months postoperatively to determine if an accelerated rehabilitation program was detrimental to intermediate follow-up results. The rehabilitation program included immediate full weightbearing, using crutches as aids for 2 weeks only, and a Generation II rehabilitation brace set at full range of motion for 2 weeks followed at 2 weeks by bicycle riding and strengthening exercises. Return to sports was allowed at 4 months for nonpivoting sports and at 6 months for level 1 sports involving pivoting. Thirty-seven patients were available for followup. At followup, three grafts were determined to be nonfunctional (KT-1000 arthrometer testing indicating > 4 mm of side-to-side difference). The other 34 patients had good or excellent results, with all returning to their preinjury levels of sport with a brace. Early accelerated rehabilitation after anterior cruciate ligament reconstruction with semitendinosus and gracilis tendon autograft and a ligament augmentation device does not seem to affect the results adversely. Results in this series were as good as or better than other series using the same reconstructive technique.

A biomechanical comparison between the central one-third patellar tendon and the residual tendon

The purpose of this study was to compare the tensile strength of the central one third patellar tendon--as used for reconstruction of the anterior cruciate ligament--to that of the residual patellar tendon. Ten matched pairs of human cadaveric knees were used for this study, each specimen consisting of an intact patella-patellar tendon-proximal tibial unit. One knee from each pair was randomly selected for removal of both the medial and lateral one third of the patellar tendon, leaving the central one third intact. The contralateral knee of each pair underwent removal of the central one third of the patellar tendon, leaving the residual two thirds intact. Each specimen was then mounted in a materials testing machine and tensile tested to failure at a strain rate of 100%.s-1. The most important result to emerge from these experiments was that there was no significant difference in maximum force to failure for the residual patellar tendon compared to the central one third. Thus any thought that removal of the central one third as a graft still leaves a tendon twice as wide and therefore twice as strong as a graft is dispelled by these experiments.

Strength of the quadriceps femoris muscle and functional recovery after reconstruction of the anterior cruciate ligament. A prospective, randomized clinical trial of electrical stimulation

Immediately after reconstruction of the anterior cruciate ligament, 110 patients were randomly assigned to treatment with high-intensity neuromuscular electrical stimulation (thirty-one patients), high-level volitional exercise (thirty-four patients), low-intensity neuromuscular electrical stimulation (twenty-five patients), or combined high and low-intensity neuromuscular electrical stimulation (twenty patients). All treatment was performed isometrically with the knee in 65 degrees of flexion. All of the patients participated in an intensive program of closed-kinetic-chain exercise. After four weeks of treatment, the strength of the quadriceps femoris muscle and the kinematics of the knee during stance phase were measured. Quadriceps strength averaged 70 per cent or more of the strength on the uninvolved side in the two groups that were treated with high-intensity electrical stimulation (either alone or combined with low-intensity electrical stimulation), 57 per cent in the group that was treated with high-level volitional exercise, and 51 per cent in the group that was treated with low-intensity electrical stimulation. The kinematics of the knee joint were directly and significantly (p < 0.05) correlated with the strength of the quadriceps. There was a clinically and statistically significant (p < 0.05) difference in the recovery of the quadriceps and the gait parameters according to the type of operation that had been performed: the patients who had had reconstruction of the anterior cruciate ligament with use of an autologous patellar-ligament graft did poorly compared with the other patients.

Histological changes associated with an artificial anterior cruciate ligament

AIMS

To investigate the histopathological features of the synovial lining of the knee following implantation of an artificial cruciate ligament.

METHODS

Eighty two patients underwent anterior cruciate ligament reconstruction for chronic, symptomatic instability of the knee. The cruciate ligament was reconstructed with a scaffold type prosthetic ligament. All patients underwent arthroscopy at the time of cruciate reconstruction and also as a "second look" procedure at a mean 26.5 months later, at which time synovial biopsy specimens were obtained in all cases.

RESULTS

The most frequent histological finding was granulomatous synovitis in 48% (39/82) of patients. Particulate polyester debris produced a greater response than carbon fibres. In 24% (20/82), nonspecific inflammation was present and in 28% (23/82) the synovium was considered normal. When the prosthetic ligament was fully covered by soft tissue in-growth, a granulomatous reaction was present in 42% (24/57), irrespective of whether the ligament was partially or totally uncovered. Stabilisation of the joint did not prevent subsequent deterioration in the articular cartilage; other factors such as increasing patient age, interval between injury and reconstruction and altered knee kinematics after reconstruction are probably important. Granulomatous synovitis was not associated with progressive chondral changes.

CONCLUSIONS

Although present in 48% of cases, granulomatous synovitis was not shown to have adverse effects on either chondral surface or the prosthetic material of the ligament. Rupture of the implant is caused by mechanical factors and granulomatous synovitis is not responsible for implant failure.

Anterior cruciate ligament patellar tendon reconstruction: it is probably better to leave the tendon defect open!

The purpose of our prospective study was to establish whether or not in anterior cruciate ligament (ACL) patellar tendon reconstruction the tendon defect has to be closed. In 50 consecutive ACL patellar tendon reconstructions, the tendon defect was randomly closed (group I) or left open (group II). The following data were recorded from all patients on the 4th and 14th days post operation: range of motion (ROM), pain at rest, pain and validity at isometric contraction, ability of bent leg raising (at 4th day) and straight leg raising (at 14th day). All the patients underwent ultrasonographic examination after 3 months and X-ray scanning at 6 months post operation. Forty patients underwent a CT-scan examination at 6 months. Thirty patients underwent isokinetic testing between 10 and 12 months post operation. Evaluating the immediate post operation data, no statistically significant differences emerged between the two groups. Ultrasonography showed in 68% of the knees of group I (defect closed) a thickened patellar tendon (PT), while in 60% of group II it was of normal thickness. No patients of either group developed patella infera by X-ray evaluation 6 months post operation. CT scans at 6 months showed that 100% of the knees of group I had a thickened PT in toto (nearly twice as thick as normal). Scar tissue was present not only in its central third but also in more than half of the cases in the medial and lateral third. In group II 75% of the patients had a normal thickness PT and 25% presented with only a minimal thickening. Scar tissue was distinguished only at its central third.(ABSTRACT TRUNCATED AT 250 WORDS)

Healing of the patellar tendon after harvesting of its mid-third for anterior cruciate ligament reconstruction and evolution of the unclosed donor site defect

The purpose of this study was (a) to evaluate by ultrasonography the healing of the patellar tendon after its mid-third was removed for anterior cruciate ligament (ACL) reconstruction in two randomized groups of patients in whom the tendon donor site was either left open or closed; (b) to compare clinical, radiographic, and isokinetic studies of these two groups to evaluate the incidence of patellofemoral disorders. We performed 61 ACL reconstructions (22 males, 39 females) using the arthroscopically assisted in-out technique. All operations were performed by the same surgeon, and the patients were all subjected to the same postoperative protocol. The tendon defect was left open in 25 subjects (group A) and was closed in 36 subjects (group B). Postoperative patellar tendon behavior was evaluated in these two groups by ultrasonography at 3, 6, 9, and 12 months. The vertical position of the patella was measured in the follow-up lateral view at 45 degrees of flexion and compared to that of the untreated knee. A clinical evaluation was performed throughout the follow-up period, and patellofemoral problems (pain, stiffness, patello-femoral crepitus) were evaluated and recorded using a modified Larsen and Lauridsen rating scale. Isokinetic evaluation was carried out at 6 months, and a quadriceps index of the two groups was recorded. Ultrasonography showed that healing of the patellar tendon initially progressed with a compensatory hypertrophy in width and thickness. The width was greater in group B (P < 0.01). In group A we observed in the cross-sections a characteristic image of two cords separated by a low signal bridge which we defined as a "binocular pattern." Areas of high ultrasound signal intensities persisted after 1 year in the open group; such areas were filled with scar tissue. In the closed group the ultrasound tendon signal returned to normal at 1 year. At 6 months the clinical, radiographic and isokinetic findings did not significantly differ between the open and closed groups. We conclude that defect closure after patellar tendon harvesting does not significantly influence the extensor apparatus.

[Replacement of the anterior cruciate ligament by a PET prosthesis (Trevira extra-strength) as a salvage procedure in chronically unstable previously operated knee joints. Intermediate to long-term results of a clinical study]

Thirty-one salvage cases of chronically unstable previously operated knees were stabilized by an anterior cruciate ligament prosthesis of polyethyleneterephthalate (Trevira hochfest) and additional repair of concomitant lesions. The patients were followed up at yearly intervals. For the final follow-up after 4.4 years 27 patients could be evaluated clinically, radiologically and by several scores. The pre-operative Lysholm score was 59.8 (+/- 16.7). It was raised significantly by the operation to 75.4 (+/- 18.9) after 1 year, but then gradually decreased to 71.4 (+/- 19.6) at the final examination. Similar values were reached for the other scores (OAK, IKDC, VAS). The degree of activity (as estimated by the Tegner activity scale) increased from 2.0 (+/- 2.1) to 3.1 (+/- 1.9). Pre-operative anterior translation revealed a side-to-side difference of 7.5 (+/- 3.4) mm. The stability, which was restored by the operation, gave way a little in the first 2 years up to a side-to-side difference of 2.1 (+/- 2.5) mm, but then remained constant and was measured 2.3 (+/- 2.9) mm after 4.4 years. On the whole, the patients gained a significant improvement from the operation in all investigated parameters. Major complications included 5 ruptures of the synthetic ligament (1 by material fatigue), 1 avulsion of a staple, 1 supracondylar fracture due to 3 closely located staples, 4 cases of arthrofibrosis and 1 case of chronic knee irritation. The gradual deterioration of the operated knees within the follow-up period is mainly caused by the pre-existing chronic degenerative changes, which progress in spite of a sufficient stabilization of the central pivot.

Arthroscopy-assisted anterior cruciate ligament reconstruction using patellar tendon substitution. Two- to four-year follow-up results

The purpose of this retrospective study was to evaluate clinically, functionally, and objectively our initial experience using free, autogenous middle third patellar tendon for anterior cruciate ligament reconstruction without extraarticular augmentation in 62 of 75 patients (80% followup) who were available for clinical review at a minimum 2-year followup. Subjective, clinical, functional, Cybex dynamometer, and KT-1000 arthrometer tests were performed along with modified tests of the Hospital for Special Surgery, Noyes Cincinnati, Tegner, and Lysholm knee rating scales. Ninety-two percent had a negative pivot shift at followup. The mean Cybex dynamometer extension deficits postoperatively were 9% and 7% at 180 and 240 deg/sec. Mild patellar pain symptoms were noted in 18%. The reoperation rate was 10% with a mild flexion contracture as the most common reason. The Hospital for Special Surgery scoring scale postoperatively was 88; Noyes, 86; Lysholm, 88; and Tegner, 6. Mean postoperative single-legged and vertical jump indices were 88% and 87%, respectively. The KT-1000 arthrometric evaluation postoperatively revealed a mean maximum manual difference of 0.3 mm; 92% of the patients had a maximum manual difference of < or = 3 mm. Subjectively, 95% indicated that they would undergo the procedure again. Early results demonstrate excellent stability, preservation of motion, and encouraging evaluations by scoring scales and arthrometric evaluation.

The relationship between subjective knee scores, isokinetic testing, and functional testing in the ACL-reconstructed knee

It is important to examine the functional relationships between commonly performed clinical tests and to resolve inconsistencies in previous investigative results. The purpose of this study was to determine if a correlation exists between three commonly performed clinical tests: isokinetic isolated knee concentric muscular testing, the single-leg hop test, and the subjective knee score in anterior cruciate ligament reconstructed knees. To determine if a relationship exists would be beneficial to clinicians in determining patient progression, treatment modification, and return-to-sport objective parameters. Several investigators have analyzed two of these parameters, but no one has investigated three parameters to date. Additionally, this study explored the concept of limb acceleration and deceleration during high-speed isokinetics and its relationship to function. Fifty patients were randomly selected (29 males) with a mean age of 23.7 years (range 15-52). The subjects completed a subjective knee score questionnaire that rated symptoms (pain, swelling, giving way) and specific sport function and completed an overall knee score assessment. The patients were then evaluated performing three one-legged functional tests: 1) hop for distance, 2) timed hop, and 3) cross-over triple hop. Isokinetic testing was performed on a Biodex dynamometer at 180, 300, and 450 degrees/sec for knee extension/flexion. The patients' mean value of the self-assessed knee rating was 86 points. Sixty-four percent of the patients exhibited normal limb symmetry (within 85%) on all three single-leg hop tests. Sixteen percent exhibited quadriceps strength at least 90% of the contralateral limb isokinetically. A positive correlation was noted between isokinetic knee extension peak torque (180, 300 degrees/sec) and subjective knee scores, and the three hop tests (p < 0.001). A statistical trend was noted between knee extension acceleration and deceleration range at 180 and 300 degrees/sec for the timed hop test and triple cross-over hop (r = 0.48, r = 0.49, r = 0.51, r = 0.49). No positive correlations were found for isokinetic test results for the knee flexors.

Pain after use of the central third of the patellar tendon for cruciate ligament reconstruction. 33 patients followed 2-3 years

We performed reconstruction of the anterior cruciate ligament in 33 patients using the central third of the patellar tendon. In 20 patients we did an arthroscopically-assisted procedure, while 13 patients had an additional mini-arthrotomy through the gap in the patellar tendon. After 2-3 years the subjective knee function, according to the Lysholm score, was excellent or good in 18 knees and fair or poor in 15 knees, mainly due to anterior knee pain. Although 18 patients complained about anterior knee pain, only 1 patient required further surgery. After the operation the patella had a lower position. A flexion contracture was found in 7 patients, and 13 had heterotopic bone formation at the apex of the patella. Although stability was restored in 31 of the 33 reconstructed knees, anterior knee pain was a frequent complication. There were no correlations between the anterior knee pain and patellar height, flexion contracture or heterotopic bone formation.

Review of the afferent neural system of the knee and its contribution to motor learning

Understanding the afferent neural system of the knee is considered to be vital to rehabilitation planning. An intricate relationship exists involving the afferent neural receptors in the inert and contractile tissues of the knee. Traditional rehabilitation strategies may not exploit this extensive afferent neural system. Closed kinetic chain functional training (CKCFT) may provide a method for more effectively rehabilitating an injured or reconstructed knee. The rationale for CKCFT has traditionally focused on mechanical aspects. Sensorimotor integration through motor learning is believed to be an important component of CKCFT. The purposes of this review are to discuss: 1) the afferent neural system of the knee with emphasis on the mechanoreceptors, 2) the influence of the afferent neural system of the knee on motor learning, and 3) how CKCFT uses the afferent neural system of the knee and motor learning during knee rehabilitation. This review reinforces the use of CKCFT in knee rehabilitation plans.

Donor-site morbidity after harvest of a bone-tendon-bone patellar tendon autograft

The effects of closure of the peritendineum and bone grafting of the patellar defect after harvest of the bone-tendon-bone patellar tendon autograft was investigated prospectively in two groups of 25 patients. Anterior cruciate ligament (ACL) reconstruction was performed with minimally invasive techniques either arthroscopically or via mini-arthrotomy. Patellar height, size of bony and tendon defects, and overall result were followed up for 2 years postoperatively. The results showed that closure of the peritendineum enhances healing of the patellar tendon defect and restores a normal appearance of the tendon within 2 years. We have stopped bone grafting the patellar defect with cancellous bone because of the risk of formation of painful spurs at the inferior pole of the patella which occurred in 36% of patients.

Comparison of perioperative morbidity of anterior cruciate ligament autografts versus allografts

We present a retrospective report of 50 patients (31 autograft and 19 allograft patients) who underwent arthroscopic bone-patellar tendon-bone anterior cruciate ligament (ACL) reconstructions between August 1988 and September 1990. All patients were followed for a minimum of 2 years. The purpose of this study was to analyze each group regarding hospital stay, swelling, thigh atrophy, laxity, strength, endurance, range of motion, patellofemoral symptoms, and complications. We found no statistical difference between autograft or allograft ACL reconstructions with regard to perioperative morbidity.

Deterioration of patellofemoral articular surfaces after anterior cruciate ligament reconstruction

One hundred eighty-seven patients who had undergone intraarticular anterior cruciate ligament reconstruction using either a fresh-frozen allogeneic tendon or central third autogenous pateller tendon 3 to 89 months previously were arthroscopically evaluated. The focus was on secondary changes of the patellofemoral joint at the time of second-look arthroscopy. Overall, 93 knees deteriorated, 74 knees remained unchanged, and 14 improved. The deteriorative changes were predominantly located around the central ridge of the patellae, although all but two knees remained free from anterior knee pain. Statistical multivariate analysis showed surgical approach by conventional medial parapatellar incision and use of the central one-third of the autogenous patellar tendon graft as possible risk factors for the deterioration, although chi-square analysis failed to demonstrate statistical significance for the latter.

Morphometry of the semitendinosus and gracilis tendons with application to anterior cruciate ligament reconstruction

The length and cross-sectional area of human semitendinosus and gracilis tendons were measured in both single- and multi-strand configurations for the purpose of anterior cruciate ligament graft preparation. The average lengths of the semitendinosus and the gracilis tendons were 235 +/- 20 mm (mean +/- SD) and 200 +/- 17 mm, respectively. The cross-sectional area of a doubled semi-tendinosus tendon (two strands) was significantly less than that of a 10-mm-wide patellar tendon graft (P < 0.001). The cross-sectional area of the tripled semitendinosus tendon (three strands) and the 10-mm-wide patellar tendon were similar. Doubling of the combined semitendinosus and gracilis tendons (four strands) and tripling of this combination (six strands) resulted in a significantly greater cross-sectional area in comparison to the 10-mm-wide patellar tendon (P < 0.05, four strands; P < 0.001 six strands). This investigation demonstrates that anterior cruciate ligament grafts fashioned using multiple-strand combinations of the semitendinosus and gracilis tendons result in a cross-sectional area that is comparable to the bone-patellar tendon-bone graft. This is an important finding since cross-sectional area reflects the intra-articular volume of collagenous tissue. This information should be helpful to surgeons considering using the hamstring tendons as an anterior cruciate ligament graft.