Arthroscopic release of the posterior compartments in the treatment of extension deficit of knee

Fibroarthrosis following knee injury or synovial disease is characterized by the presence of dense adhesions filling the entire joint cavity and the fibrotic involvement of periarticular structures. In this particular subset of knee stiffness, both the open and the arthroscopic treatment may fail not addressing all pathology. The aim of the present study was to evaluate the efficacy of an all-arthroscopic treatment for the flexion contractures addressing both the intra-articular posterior adhesions and the fibrotic periarticular structures. From 2003 through 2007, 18 patients of the knee underwent on arthroscopic posterior arthrolysis with release of both gastrocnemius tendons using the trans-septal technique. The median interval between the index procedure and the arthrolysis was 15 (4–22) months. Eight patients had a previous arthroscopic arthrolysis, performed in other hospitals, and two patients had two arthroscopic procedures after the index procedure which failed to regain the extension deficit. The passive extension deficit averaged 34° preoperatively (16°–44°). Six patients underwent a two-staged procedure: the first surgery addressed the presence of adhesions in the suprapatellar pouch and the medial and/or lateral gutters, to regain the flexion of the knee. At final follow-up, the passive extension deficit averaged 3° (0°–5°). In all patients, total knee arc of motion increased from 60° (30°–85°) to 95° (5°–110°). The trans-septal portal allows a safe approach of the posterior compartments and allows addressing pathology of both compartments and the release of gastrocnemius tendons.     

Static progressive stretch improves range of motion in arthrofibrosis following total knee arthroplasty

Arthrofibrosis is a relatively common complication after total knee arthroplasty that negatively affects function and quality of life. Static progressive stretching is a technique that has shown promising results in the treatment of contractures of the elbow, ankle, wrist and knee. This study evaluated a static progressive stretching device as a treatment method for patients who had refractory knee stiffness after total knee arthroplasty. Twenty-five patients who had knee stiffness and no improvement with conventional physical therapy modalities were treated with the device. After a median of 7 weeks (range, 3–16 weeks), the median increase in range of motion was 25° (range, 8–82°). The median gain in knee active flexion was 19° (range, 5–80°). Ninety-two percent of patients were satisfied with the results. The authors believe static progressive stretching devices may be an effective method for increasing the ranges of motion and satisfaction levels of patients who develop arthrofibrosis after total knee arthroplasty.     

Arthroscopic arthrolysis for the treatment of stiffness after total knee replacement gives moderate improvements in range of motion and functional knee scores

Twenty-two total knee replacements (TKR’s) were treated for stiffness with arthroscopy and arthrolysis. The median follow-up was 38 months. No patients were lost to follow up. Extensive scarring was found and debrided in all of the knees. The mean Oxford Knee Score improved from 42.6 (±7.5) to 36.3 (±8.5) (P < 0.05) with TKR and from 36.3 (±8.5) to 29.3 (±9.0) (P < 0.05) with arthroscopic arthrolysis. The mean arc of motion improved from 8–69° post-TKR to 3–105° on table, but declined slightly to 4–93° (P < 0.05) at most recent review. Arthroscopic arthrolysis compares well with other methods of treatment for stiffness with regard to improvements in range of motion and functional knee scores.     

A long-term study of anterior cruciate ligament allograft reconstruction

We retrospectively reviewed the long-term clinical outcome of unilateral arthroscopic anterior cruciate ligament (ACL) allograft reconstruction. From October 1995 to December 1997, 64 arthroscopic ACL reconstructions were performed. Multiligamentous knee injuries and ACL injuries in polytrauma patients were excluded and out of the remaining 60 patients 55 were available for follow-up. Three patients had suffered a rerupture caused by major trauma. One patient had a rerupture without significant trauma and one failure was caused by deep infection. These five patients were revised. Fifty patients (36 males, 14 females) were included in the final follow-up. At the time of evaluation, the mean duration of follow-up was 10 years and 6 months. All patients were examined by an independent examiner. Seven patients had an extension lag (<5°) and all patients had a knee flexion of at least 120°, with a mean flexion of 135 ± 5° compared to 135 ± 8°. At the time of follow-up, the median IKDC score was 97 (74–100). The Lysholm scoring scale had a median value of 95 (76–100). The median sports level on the Tegner scale was 6 (4–9). The one-leg-hop test showed a mean value of 95 ± 5%. One patient did not perform the one-leg-hop test because of recent surgery to the Achilles tendon. In conclusion, the tibialis anterior or tibialis posterior tendon allograft ACL reconstruction produced good clinical results in the majority of patients at long-term follow-up.     

Second-look arthroscopic findings of 208 patients after ACL reconstruction

The aim of this study is to report the arthroscopic subjective findings of reconstructed anterior cruciate ligament (ACL) with good clinical outcome. Graft used for reconstruction was either patella bone-tendon-bone (PBTB) autograft or hamstring tendon [quadrupled semitendinous and gracilis tendon (QSGT)] autograft. From March 1997 to September 2003, among 716 ACL reconstructions 209 knees (208 patients) were available for second-look arthroscopy at a mean 21.2-month (range, 14–70 months) postoperative period. The second-look arthroscopy focused on the evaluation of (1) continuity of the reconstructed ACL graft, (2) subjective graft tension using a probe, (3) the extent of synovial coverage, (4) the prevalence of cyclops or cyclops-like lesion, and (5) bony change after notchplasty. Patellar tendon autograft was used in 80 knees, hamstring tendon autograft in 129 knees. Just prior to second-look arthroscopy two objective clinical evaluations, KT-2000 arthrometer and Lysholm knee score, were performed to verify good clinical outcomes. A comparison between the hamstring tendon group and the patella tendon group, hamstring group showed slightly better results in Lysholm knee scores and KT-2000 arthrometer but there were no statistically significant differences (p>0.05). Undetected partial graft tear was seen in 21 knees (10%). With regard to graft tension, a total of 181 grafts (87%) showed normal tension and 28 (13%) showed slight lax tension. The overall synovial coverage was poor in nine (4%) knees. The synovial coverage was slightly better in the hamstring tendon group. A total of 45 knees (21.5%) showed cyclops-like lesion in variable sizes and locations. Reformation of the notch was seen in 85 knees (40%). In conclusion, the findings of second-look arthroscopy of reconstructed ACL in good clinical outcome patients showed approximately 10% partial graft tear, 5% poor synovial coverage, 20% cyclops-like lesion, and 40% some notch reformation.     

Patient function after a posterior stabilizing total knee arthroplasty: cam–post engagement and knee kinematics

Even though posterior substituting total knee arthroplasty has been widely used in surgery, how the cam–post mechanism (posterior substituting mechanism) affects knee joint kinematics and function in patients is not known. The objective of the present study was to investigate posterior femoral translation, internal tibial rotation, tibiofemoral contact, and cam–post engagement of total knee arthroplasty patients during in vivo weight-bearing flexion. Twenty-four knees with a PS TKA were investigated while performing a single leg weight-bearing lunge from full extension to maximum flexion as images were recorded using a dual fluoroscopic system. The in vivo knee position at each targeted flexion angle was reproduced using 3D TKA models and the fluoroscopic images. The kinematics of the knee was measured from the series of the total knee arthroplasty models. The cam–post engagement was determined when the surface model of the femoral cam overlapped with that of the tibial post. The mean maximum flexion angle for all the subjects was 112.5 ± 13.1°. The mean flexion angle where cam–post engagement was observed was 91.1 ± 10.9°. The femur moved anteriorly from 0° to 30° and posteriorly through the rest of the flexion range. The internal tibial rotation increased approximately 6° from full extension to 90° of flexion and decreased slightly with further flexion. Both the medial and lateral contact point moved posteriorly from 0° to 30°, remained relatively constant from 30° to 90°, and then moved further posterior from 90° to maximum flexion. The in vivo cam–post engagement corresponded to increased posterior translation and reduced internal tibial rotation at high flexion of the posterior substituting total knee arthroplasty. The initial cam–post engagement was also mildly correlated with the maximum flexion angle of the knee (R = 0.51, p = 0.019). A later cam–post engagement might indicate an environment conducive to greater flexion. If the factors that affect cam–post engagement timing can be established, proper manipulation of those factors may improve the function of the knee after posterior substituting total knee arthroplasty.     

Measurement and comparison of the difference in normal medial and lateral knee joint opening

This paper reports the amount of medial and lateral knee joint opening in the general population. Knee joint lateral and medial opening at 20° knee flexion was quantified on manual varus and valgus stress test, respectively, with custom made device. One hundred men and women between the ages of 20–60 years were evaluated for their joint openings. Patients with previous knee surgeries or chronic knee pains were excluded from the study. Measurements were done twice by two different orthopedic surgeons who were blinded from each other. The mean age of the study group was 39 years (range 20–60 years) and 43 years for women (range 20–60 years) and 34 years for men (range 20–60). The mean lateral and medial knee joint space opening was 7.0° (range 3–9°) and 4.1° (range 2–7°), respectively, in the overall population; in the male population, it was 6.7° (range 3–9°) and 3.9° (range 2–7°), respectively, and in the female population, it was 7.2° (range 3–9°) and 4.3° (range 3–7°), respectively. Conversion to displacement in millimetres, the overall mean lateral and medial joint displacement was 9.3 mm (range 5.1–13.6 mm) and 4.8 mm (range 3.5–10.7 mm), respectively; for males, it was 9.1 (range 5.1–11.9 mm) and 4.6 mm (range 3.5–7.9 mm), respectively, for females, it was 9.8 mm (range 7.2–13.6 mm) and 4.9 mm (range 3.7–10.7 mm), respectively. The prevalence of the overall population that exceeds 6 mm or more lateral joint space opening was 91% (male 90% and female 92%) and medial joint space was 8% (male 4% and female 12%). Statistically, significant differences were seen between medial and lateral opening in male, female and the overall population (p<0.001). The female population exhibited wider opening in both medial and lateral joint opening than the male population (p<0.05). The interexaminer reliability showed no significant difference (p>0.05). More than 91% of the Korean population showed wide lateral joint space opening in the bilateral knee. However, none complained of functional instability or symptoms except for non-pathologic laxity detected by the physician. We strongly recommend bilateral comparison of the knee that has wide lateral joint opening.     

Arthroscopic posteromedial capsular release for knee flexion contractures

Extension deficits of the knee can cause functional limitations in patients after knee surgery or injury. Most frequently, they are treated with manipulations, arthroscopic anterior compartment debridements, or open posterior capsular releases once nonoperative treatment fails. However, an arthroscopic posteromedial capsular release to manage flexion deficits has yet to be studied comprehensively. Arthroscopic posteromedial capsular releases of the knee can result in improved knee motion postoperatively. An arthroscopic posteromedial capsular release involves sectioning the posteromedial capsule at its meniscofemoral portion, midway between its femoral attachment and its posterior horn medial meniscus junction. A review of 15 patients who underwent this operation was performed. Passive knee extension and flexion was measured in patients in the supine position using a goniometer at preoperative evaluations, under anesthesia prior to and immediately after the posteromedial capsular release, and at postoperative follow-up evaluations. The average time from the arthroscopic posteromedial capsular release to the final postoperative follow-up was 24.1 months. Preoperative knee extension averaged 14.7° in 15 patients. The average immediate postoperative knee extension averaged −0.9°. At the final postoperative follow-up, knee extension averaged 0.7°. Overall knee motion improved from an average arc of motion of 101.6°–129.4°. Arthroscopic posteromedial capsular releases and the concurrent postoperative rehabilitation program were effective in the treatment of knee extension deficits. The encouraging results of this study compare well to data presented in open posterior capsular release studies. We believe that arthroscopic posteromedial capsular releases are an effective means to address symptomatic knee extension deficits.     

Prevention of permanent arthrofibrosis after anterior cruciate ligament reconstruction alone or combined with associated procedures: a prospective study in 443 knees

We prospectively determined the effectiveness of an immediate knee motion and early intervention program to prevent permanent motion limitations in a consecutive series of patients who had anterior cruciate ligament autogenous patellar tendon reconstruction for isolated rupture (219 knees) or combined with other procedures (224 knees). The subjects were placed into either a progressive or delayed rehabilitation program and were followed for at least 12 months postoperatively. At follow-up a normal range of motion (0° to at least 135°) was found in 436 knees (98%), and mild losses of extension (–5°) were found in 7 knees. Twenty-three knees (5%) required interventions; 9 had extension casts, 9 had gentle manipulations under anesthesia, 3 had arthroscopic débridements, and 2 had continuous epidural anesthetic and inpatient therapy. All of these 23 knees regained full motion. The 7 patients with mild losses of extension had refused treatment intervention. The 0% incidence rate of permanent arthrofibrosis, and 0.7% reoperation rate for knee motion limitations, demonstrated the effectiveness of our program. Received: 6 December 1999 Accepted: 20 April 2000     

Tibiofemoral kinematic analysis of knee flexion for a medial pivot knee

The performance of total knee arthroplasty in deeply flexed postures is of increasing concern as the procedure is performed on younger, more physically active and more culturally diverse populations. Several implant design factors, including tibiofemoral conformity, tibial slope and posterior condylar geometry have been shown directly to affect deep flexion performance. The goal of this study was to evaluate the kinematics of a fixed-bearing, asymmetric, medial rotation arthroplasty design in moderate and deep flexion. Thirteen study participants (15 knees) with a medial rotation knee arthroplasty were observed performing a weight-bearing lunge activity to maximum comfortable flexion and kneeling on a padded bench from 90° to maximum comfortable flexion using lateral fluoroscopy. Subjects averaged 74 years of age and nine were female. At maximum weight-bearing flexion, the knees exhibited 115° of implant flexion (102°–125°) and 7° (−3° to 12°) of tibial internal rotation. The medial and lateral condylar translated posteriorly by 2 and 5 mm, respectively. At maximum kneeling flexion, the knees exhibited 119° of implant flexion (101°–139°) and 5° (−2° to 14°) of tibial internal rotation. The lateral condyle translated posteriorly by 11 mm. The medial rotation knee exhibited motion patterns similar to those observed in the normal knee, but less tibial rotation. The medially conforming articulation beneficially controls femoral AP position in deep flexion, in patients who require such motion as part of their lifestyle. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Mid-term results with a highly congruous mobile-bearing knee prosthesis

Two hundred and six consecutive total knee arthroplasties were performed in 180 patients with a highly congruous mobile-bearing knee prosthesis. At mean follow-up of 78 months (range: 60–102 months), the outcomes of 181 knees in 158 patients were evaluated using the American Knee Society’s Knee and Functional scoring system and Radiological scoring system. Mean values for Knee and Function scores were 92.6 and 81.1, respectively versus 51.8 and 43.4 preoperatively; mean flexion range was 113.6° versus 110.8° preoperatively. There were no cases of bearing dislocation and no radiological signs of loosening or osteolysis. Secondary patella resurfacing was done in 7 of 52 knees in which the patella was not primarily resurfaced. Arthroplasty survival with revision for aseptic loosening as the endpoint was 100% (95% CI: 97.7–100) at 5 years and at 8 years (95% CI: 87.2–100); with revision of the arthroplasty for any reason including one revision for infection as the endpoint, survival was 99.5% (95% CI: 96.9–100) at 5 years and at 8 years (95% CI: 86.9–100). The overall results were satisfactory and compared with those of other mobile-bearing knee prostheses featuring full or partial congruence. No significant differences were noted for range of motion, knee scores and function scores between two subsets of knees that received a bearing allowing only rotation or rotation and 5 mm anteroposterior translation. Longer follow-up is needed to evaluate possible benefits of high congruence and of specific modes of bearing mobility with respect to wear and bony fixation.     

Is previous knee arthroscopy related to worse results in primary total knee arthroplasty?

According to literature, knee arthroscopy is a minimal invasive surgery performed for minor surgical trauma, reduced morbidity and shortens the hospitalization period. Therefore, this type of surgery before total knee arthroplasty (TKA) could be considered a minor procedure with minimum postoperative complication. A retrospective and cohort series of 1,474 primary TKA was performed with re-assessment after a minimum follow-up period of 2 years: 1,119 primary TKA had no previous surgery (group A) and 60 primary TKA had arthroscopic debridement (group B). All the patients underwent a clinical and radiological evaluation as well as IKS scores. Statistical analysis of postoperative complications revealed that group B had a higher postoperative complication rate (P < 0.01). In this group, 30% of local complications were re-operated and 8.3% of these cases underwent revision TKA (P < 0.01). The mean interval between arthroscopy and primary TKA was 53 months. However, statistical analysis did not reveal a direct correlation between arthroscopy/primary TKA interval and postoperative complications/failures (P = 0.55). The Kaplan–Meier survival curves showed a survival rate of 98.1 and 86.8% at 10 years follow-up for groups A and B, respectively. Our data allow us to conclude that previous knee arthroscopy should be considered a factor related to postoperative primary TKA outcomes as demonstrated by the higher rate of postoperative complications and failures (P < 0.001) as well as a worse survival curve than group A.     

Minimally invasive unicompartmental knee replacement: retrospective clinical and radiographic evaluation of 83 patients

We performed a retrospective clinical and radiographic evaluation of 83 nonconsecutive patients operated in our institute between February 1996 and March 2003 with a mean follow-up of 60 months to assess the efficiency of unicompartmental knee replacement (UKR) performed with a minimally invasive technique. The aim of this study was to correlate the clinical outcome with the pre- and post-operative alignment and with implant positioning on coronal and sagittal plane. Eighty-three nonconsecutive patients (60 males, 23 females) underwent cemented UKR (De Puy Preservation Uni with all-poly tibial component), for both medial OA (80 patients) and AVN of the medial femoral condyle (3 patients). All patients were available at final follow-up evaluation, and they all presented an evident varus alignment at pre-operative clinical and radiographic evaluation. At radiographic measurement, we considered a knee with femoro-tibial angle (FTA) > 175° as varus knee, 170° < FTA < 175° as normal knee and a knee with a FTA < 170° as a valgus knee. Moreover, we considered a tibial plateau angle (TPA) > 90° for valgus knee and a TPA < 90° for varus knee. According to Hospital for Special Surgery (HSS) scoring system, at a mean follow-up of 60 months, 61 (74%) cases were excellent (100-85 points), 15 (18%) cases were good (84-70 points) and 7 cases (8%) had fair results (<70 points). In our series, patients with an excellent clinical result presented a mean varus deformity of 7.2° (3.6°–10.8°) pre-operatively. According to literature, we demonstrated that a small amount of undercorrection with a small amount of residual varus deformity of 3°–5° is the goal to be reached in order to avoid both rapid degeneration of the nonreplaced compartment and the premature loosening of the replaced compartment. We performed a mean axial correction of 5° (SD 3.9°), leaving a mean axial varus deformity of 2.2° in the excellent group. In our series, the group with excellent results also showed a post-operative PTS of 7° (2.4°–11.6°), while mean pre-operative PTS was 6.5° (2.7°–10.3°). In this study, results have shown that minimally invasive UKR producing a small amount of varus undercorrection in selected patients with medial tibio-femoral osteoarthritis or moderate avascular necrosis of the medial femoral condyle provides excellent clinical and functional results. Overcorrection of varus malalignment with a UKR may produce both rapid degeneration of the lateral tibio-femoral compartment and the early failure of the replaced compartment.     

Abnormal bone scans in anterior cruciate ligament deficiency indicate structural and functional abnormalities

Many patients with anterior cruciate ligament (ACL) deficiency have an abnormal bone scan. This finding has not yet been explained. Suggested explanations include intra-articular (structural) or kinematic (functional) abnormalities. We examined the relationship between bone scintigraphy and cartilage degeneration or meniscal lesions in the ACL-deficient knee in 95 consecutive patients who had bone scintigraphy 1–3 days prior to arthroscopic ACL reconstruction. Intra-articular abnormalities of the knee did not explain all scintigraphic patterns of this study. We did not find clinically useful positive predictive values for scintigraphic patterns considered to indicate cartilage degeneration or a lateral meniscus lesion. A clinically useful positive predictive value was found only for medial meniscus lesions when time since ACL rupture was more than 18 months, and for local cartilage degeneration when markedly increased uptake was seen when time since ACL rupture was more than 4 months. Considering these findings, alternative explanations are discussed, based on specific aspects of abnormal kinematics and adaptive bone metabolism of the ACL-deficient knee. Received: 15 October 1999/Accepted: 25 February 2000     

Late results after arthroscopic partial medial meniscectomy

In a retrospective study, 100 patients underwent a clinical and radiological follow-up examination after a minimum of 7 years (range 7.0–9.3 years) following an arthroscopic partial medial meniscectomy. None of these patients had associated intra-articular lesions, apart from minor chondral damage (max. grade 2 Outerbridge classification; < 1 cm²) of the medial compartment at the time of the primary arthroscopy. According to the modified Marshall score, the follow-up evaluation showed excellent clinical results in 96%. Nevertheless, the radiological outcome, as measured by comparing preoperative and postoperative X-rays, demonstrated a development or progression of the osteoarthritis of the affected knee joint in 33%, with a statistically significant correlation between the radiological and clinical outcomes (P < 0.05). The age of the patients at the time of operation and any angular deformity of the knee joint did not influence the radiological results. Women had a statistically significantly higher risk of developing gonarthrosis after partial medial meniscectomy than men (P < 0.05). The arthroscopic partial medial meniscectomy led to excellent subjective and functional results but could not prevent the increase or development of late degenerative changes in the medial knee compartment. Received: 18 October 1996 Accepted: 22 January 1998     

Current concepts in knee arthroscopy

Arthroscopic methods in the knee are used for diagnostic procedures and offer the surgeon a minimally invasive method for repairing a wide variety of injuries in both the acutely and chronically injured knee. These procedures are most often associated with minimal morbidity and early initiation of rehabilitation, and patients may return to work and their daily living activities at a faster rate than with conventional surgical methods. In the acute knee injury, arthroscopy has proven to be a valuable tool in defining the type and extent of the anterior cruciate ligament injury as well as providing definitive assessment of meniscal pathology. Partial menisectomy is the most commonly performed arthroscopic procedure in the knee, acounting for approximately 41% of the total arthroscopic procedures performed. Rapid advancement of arthroscopic techniques in chronic knee injuries, including patellofemoral disorders, osteochondritis dissecans, arthrofibrosis of the knee, degenerative arthritis and cruciate ligament injuries, has resulted in less surgical morbidity without disrupting uninvolved anatomy.     

Reliability and interobserver variability in radiological patellar height ratios

This study evaluated the reliability and interobserver variability of five patellar height ratios as measured by two examiners on standard radiographs: Insall-Salvati (IS), modified Insall-Salvati (MIS), Blackburne-Peel (BP), Caton-Deschamps (CD), and Labelle-Laurin (LL). Plain lateral radiographs with a knee flexion angle of 20° for IS, MIS, BP, and CD ratios and 90° for the LL method of 22 knees of 21 patients with varying pathological knee conditions were analyzed. Statistical results revealed a low interobserver variability with high correlation coefficients (0.86 for IS, 0.82 for MIS, 0.86 for BP, 0.92 for CD, and 0.81 for LL; P > 0.3) and low mean interobserver errors. However, regarding the reliability of the radiographic results of the different methods for patella alta, baja, or norma we found varying results in 68% of the patients. In two patients the patellar height was classified as alta, norma, or baja depending on the ratio used. Regarding the definitions of patellar height used by the authors of these methods, we found the lowest number of normal patellae with the IS ratio and no patella alta for the CD ratio. The LL method revealed the highest number of patella alta. The BP ratio showed intermediate results for both patella alta and baja, being the most moderate method. This study showed that there was a good interobserver reliability for the evaluation of patellar height according to the common radiological ratios. However, the high frequency of differing results between the different radiographic ratios showed that patellar height classification as “alta,”“norma,” or “baja” depends heavily on the chosen index. The differing results were due mainly to the normative patellar height data and to anatomical differences. Based on these findings we recommend a ratio using the articular surface of the patella in relation to the joint line. We recommend the BP method because it revealed the lowest interobserver variability and discriminated best among the groups alta, norma, and baja. Received: 6 December 1999 Accepted: 15 March 2000     

Functional outcome following reconstruction in chronic multiple ligament deficient knees

Multiligament knee injuries are rare but potentially limb-threatening conditions. In this study we aim to evaluate the mid- and long-term functional outcome of patients who underwent arthroscopically assisted multiple ligament reconstruction for chronic multiple knee ligament deficiency. Thirty-five patients (27 males and 8 females) with an average age of 35.1 years (range: 17–60) were included in this study. Follow-up ranged from 12 to 124 months (average: 40.3). On final follow-up patients had a mean loss of extension of 3.1°, while flexion ranged from 95° to 135° (average: 118.4°). The functional outcome according to Clancy’s criteria was excellent in 7 patients (20%), good in 14 (40%), fair in 11 (31.4%), while 3 reconstructions resulted in failure (8.6%). Patients scored an average of 4.03 (range: 1–9) in their Tegner Activity Scale, while their score in Activities of Daily Living Scale of the Knee Outcome Survey ranged from 25 to 98 with an average of 72.7. Sixteen patients returned to sporting activities and all but three returned to work. Early operative treatment of multiple ligament injuries is preferable, as it may allow for anatomic repair instead of reconstruction of ligamentous structures. This study demonstrates though, that even if acute reconstruction has not or could not be performed, reconstruction in chronic multiple ligament deficient knees should be attempted. Although this complex and technically demanding procedure rarely results in a “normal” knee, it offers in most cases very satisfactory stability and a significant improvement in knee function.     

Proprioception in the posterior cruciate ligament deficient knee

This study was undertaken to evaluate knee proprioception in patients with isolated unilateral posterior cruciate ligament (PCL) injuries. Eighteen subjects with isolated PCL tears were studied 1–234 months after injury. The threshold to detect passive motion (TTDPM) was used to evaluate kinesthesia and the ability to passively reproduce passive positioning (RPP) to test joint position sense. Two starting positions were tested in all knees: 45 ° (middle range) and 110 ° (end range) to evaluate knee proprioception when the PCL is under different amounts of tension. TTDPM and RPP were tested as the knee moved into flexion and extension from both starting positions. A statistically significant reduction in TTDPM was identified in PCL-injured knees tested from the 45 ° starting position, moving into flexion and extension. RPP was statistically better in the PCL-deficient knee as tested from 110 ° moving into flexion and extension. No difference was identified in the TTDPM starting at 110 ° or in RPP with the presented angle at 45 ° moving into flexion or extension. These subtle but statistically significant findings suggest that proprioceptive mechanoreceptors may play a clinical role in PCL-intact and PCL-deficient patients. Further, it appears that kinesthesia and joint position sense may function through different mechanisms. Received: 5 September 1998 Accepted: 25 May 1999     

Intraoperative evaluation of total knee replacement: kinematic assessment with a navigation system

Interest in the kinematics of reconstructed knees has increased since it was shown that the alteration of knee motion could lead to abnormal wear and damage to soft tissues. We performed intraoperative kinematic measurements using a navigation system to study knee kinematics before and after posterior substituting rotating platform total knee arthroplasty (TKA). We verified intraoperatively (1) if varus/valgus (VV) laxity and anterior/posterior (AP) laxity were restored after TKA; (2) if TKA induced abnormal femoral rollback; and (3) how tibial axial rotation was influenced by TKA throughout the range of flexion. We found that TKA improved alignment in preoperative osteoarthritic varus knees which became neutral after surgery and maintained a neutral alignment in neutral knees. The VV stability at 0° was restored while AP laxity at 90° significantly increased after TKA. Following TKA, the femur had an abnormal anterior translation up to 60° of flexion, followed by a small rollback of 12 ± 5 mm. TKA influenced the tibia rotation pattern during flexion, but not the total amount of internal/external rotation throughout whole range of flexion, which was preserved after TKA (6° ± 5°). This study showed that the protocol proposed might be useful to adjust knee stability at time zero and that knee kinematic outcome during total knee replacement can be monitored by a navigation system.