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PubMed2004

Optimizing patellofemoral tracking during total knee arthroplasty.

Fifty-seven patients who underwent 65 primary TKAs between 1993-1994 were retrospectively studied to identify the technical challenges and pitfalls associated with patellar resurfacing and to improve patellar tracking during total knee arthroplasty (TKA). Average patient age was 69 years. All surgeries were performed by a single surgeon (J.N.I), and the same prosthesis was used in all patients. Intraoperatively, attention was paid to avoid femoral and tibial component malrotation and prevent overstuffing of the patellofemoral joint. Preoperative limb alignment was varus in 42 knees, neutral in 6 knees, and valgus in 17 knees. Average pre-resection patellar thickness measured 23.8 mm and post-resection thickness averaged 21.5 mm. No patella-prosthesis composite was thicker than the native patella. Two (3%) knees required a formal lateral release to improve patellar tracking at surgery. Average follow-up for 53 patients (61 knees) was 5 years. At latest follow-up, 4 (6%) patients reported mild anterior knee pain, 5 (7%) patients reported pain with stairs, and 2 (3%) patients had knee crepitus without pain. No dislocations or recurrent subluxations occurred. No patient required revision surgery for patellofemoral complication. Awareness of the anatomic variability, attention to component rotation, and restoration of the normal patellar height improves patellar tracking and minimizes patellofemoral instability following TKA.

Aged↗
PubMed1989

Cementless reconstruction of massive tibial bone loss in revision total knee arthroplasty.

Reconstruction of massive proximal tibial defects caused by failed cemented total knee arthroplasty (TKA) was evaluated using cancellous allograft and a rigidly fixed tibial component. Twenty patients with massive tibial defects requiring revision TKA were operated on using this technique from December 1984 to December 1986. All these had tight mediolateral capsular structures so that satisfactory varus-valgus stability was achieved. Only three had competent posterior cruciate ligaments. The tibial component had a cobalt chromium tray with a six-inch-long smooth stem, porous undersurface, and peripheral smooth pegs. Fixation was augmented with four cancellous screws that passed through the periphery of the tray and penetrated the cortical surface of the tibia. Good fixation of the tibial component was achieved in all cases at the time of surgery. All patients achieved full weight bearing within six months, and all but two were free of walking aids at one year postoperation. None of the patients developed apparent loosening of the femoral or tibial components. Two patients complained of mild pain and one who had revision of a painful but nonloosened cemented TKA complained of severe pain. Range of motion was 93 degrees +/- 7.6 degrees. Roentgenographic evaluation showed progressive increase in radiodensity in the grafted areas one year after surgery in all knees. One knee was revised for recurrent dislocation one year postoperation and had a biopsy of the allografted area. This biopsy showed trabeculae with empty lacunae surrounded by viable new bone. Allograft reconstruction of the proximal tibia for failed cemented TKA was highly successful using morselized allograft and rigid fixation of the tibial component.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

The results of arthroscopic lateral release of the extensor mechanism for recurrent dislocation of the patella after 8 years.

We reviewed 41 knees at a mean of 4 years after arthroscopic lateral release of the extensor mechanism. The operations were performed for recurrent complete dislocation, not for subluxation, maltracking, or lateral pressure syndrome. Thirty-three of these knees were reviewed again 8 years after operation. There were 39% excellent results according to the criteria of Crosby and Insall at 4 years and 30% at 8 years. Patellar stability improved between 4 and 8 years (p < 0.01). The results in patients with subluxation of the patella on extension of the knee or generalized ligament laxity were poor; five of seven patients with these conditions were worse and had undergone another operation. With these conditions excluded, the excellent results decreased from 50% after 4 years to 37% after 8 years. The results of lateral release are better than those reported after other procedures. It is concluded that arthroscopic lateral release is the procedure of choice for patients with recurrent complete dislocation of the patella unless there is abnormal ligament laxity or subluxation on extension. The operation should not be performed in the presence of these conditions.

Adolescent↗
PubMed1985

[Transplantation of the anterior tibial tubercle by the Elmslie-Trillat technic. Indications as a function of morphotype].

The authors note that medial transplantation of the tibial tubercle diminishes the control of lateral rotation of the tibia by the quadriceps and increases stresses on the knee in varus. They have reviewed a hundred knees operated on between 1973 and 1981. Before operation, the morphology of the patients compared with a normal population was characterised by a moderate medial torsion of the femur, a marked lateral torsion of the tibia and some genu varum. After the transplant the varus was identical but in about half of the cases, lateral laxity was noted. Passive rotation of the tibia was increased and this sign was even greater in cases of marked tibial torsion. The authors conclude that this procedure is not indicated in cases of genu varum, excessive lateral tibial torsion and lateral laxity. The best indications are cases of recurrent dislocation of the patella in knees with normal rotary alignment and painful patello-femoral syndromes. They emphasise the importance of an extensive release of the lateral patellar retinaculum, of distal transplantation of the tubercle in cases of patella alta but not too much and of some degree of anterior displacement of the tubercle.

Adolescent↗
PubMed2003

Resurfacing versus not resurfacing the patella in total knee arthroplasty: 8- to 10-year results.

Patellar resurfacing in total knee arthroplasty is a topic debated in the literature. Concerns include fracture, dislocation, loosening, and extensor mechanism injury. Residual anterior knee pain has been reported when the patella is not resurfaced. One hundred patients with osteoarthritic knees were prospectively randomized to either have their patella resurfaced or left not resurfaced. All patients were treated with a single prosthesis that featured an anatomically designed patellofemoral articulation (Anatomic Medullary Knee, DePuy, Warsaw, IN) Two patients in the unresurfaced group and one in the resurfaced group required repeat surgery for patellofemoral complications. At 8- to 10-year follow-up evaluations, Knee Society Clinical Ratings scores were not different between the 2 groups. Rates of anterior knee pain with walking and stair climbing were significantly less in the resurfaced group. Eighty percent of patients with a resurfaced patella were extremely satisfied with their total knee arthroplasty versus 48% without patellar resurfacing. When satisfied and extremely satisfied patients were grouped together, there was no difference between the 2 groups.

Aged↗
PubMed2005

Cruciate-retaining total knee arthroplasty at 5 to 7 years followup.

UNLABELLED: Cruciate-retaining total knee implants may improve postoperative function in total knee arthroplasty, but whether patients experience good restoration of kinematics, undue wear, or increased revision rates is debatable. I evaluated clinical results, radiographs, and survival rates of the NexGen posterior cruciate-retaining implant at 5-7 years followup in 251 knees (198 patients) in a prospective, consecutive total knee replacement series done from 1996-1997. A consistent improvement in knee scores and range of motion was observed from preoperative evaluation through 5 years followup. Alignment remained constant and knee stability did not deteriorate. Knee Society scores were good or excellent for 90% of patients. The average range of motion was 123 degrees, and 73% of patients achieved a mean range of motion of 116 degrees -130 degrees. Mean physical quality of life measures improved from preoperative evaluation to the last followup. There were no complete or progressive radiolucencies. Four screw radiolucencies had progressive increases in diameter. Survival of the implant at 7 years was more than 98%. The NexGen posterior cruciate-retaining implant provided satisfactory kinematic and clinical results with no substantive polyethylene wear. LEVEL OF EVIDENCE: Therapeutic study, Level II-2 (poor-quality randomized controlled trial). See the Guidelines for Authors for a complete description of levels of evidence.

Aged↗
PubMed2006

The Oxford medial unicompartmental knee replacement using a minimally-invasive approach.

This prospective study describes the complications and survival of the first 688 Phase 3 Oxford medial unicompartmental knee replacements implanted using a minimally-invasive technique by two surgeons and followed up independently. None was lost to follow-up. We had carried out 132 of the procedures more than five years ago. The clinical assessment of 101 of these which were available for review at five years is also presented. Nine of the 688 knees were revised: four for infection, three for dislocation of the bearing and two for unexplained pain. A further seven knees (1%) required other procedures: four had a manipulation under anaesthesia, two an arthroscopy and one a debridement for superficial infection. The survival rate at seven years was 97.3% (95% confidence interval 5.3). At five years, 96% of the patients had a good or excellent American Knee Society score, the mean Oxford knee score was 39 and the mean flexion was 133 degrees. This study demonstrates that the minimally-invasive Oxford unicompartmental knee replacement is a reliable and effective procedure.

Adult↗
PubMed2000

[Revision in non-infected total knee arthroplasty: an analysis of 69 consecutive cases].

PURPOSE OF THE STUDY: We reviewed 69 consecutive cases of total knee arthroplasty revisions to analyze the causes of failure. MATERIAL AND METHODS: Sixty-nine total knee arthroplasty revisions were required between 1990 and 1997 for non-septic failure. Five categories of failures were identified: 30 loosenings including 11 with an initial malposition (varus position of the tibial component in 8 cases), 14 laxities (medial in 5, lateral in 5 and anteroposterior in 4), 11 stiff knees with no other clinical or radiological anomaly, 6 patellar failures (2 dislocations, 2 cases of excessive wear, 2 painful knees with a Freeman prosthesis), and 8 cases of painful knees with no other detectable anomaly. RESULTS: A three-phase reconstruction procedure was used after removing the failing TKA: 1) reconstruction of the tibia with replacement of lost bone, 2) reconstruction of the femur with balanced flexion determining the size of the implant, 3) balanced extension determining the distal/proximal position of the femoral component. A "simple" sliding prosthesis was used in 16 cases, a modular reconstruction prosthesis in 40 cases and a hinge prosthesis in 13 cases. Mean follow-up for functional and radiographic assessment after revision surgery was 37 months (59 cases) with a minimum follow-up of 1 year. The best outcome was observed in the "loosening", "laxity", and "stiffness" patients. Outcome was less favorable for the group "isolated pain" with IKS functional scores of 35.5 +/- 16 and 52.5 +/- 21. DISCUSSION: In 36 p. 100 of cases, TKA failure was related to a technical mistake (component malposition, poor ligament alignment). In 33 p. 100, failure was patient related (multiple procedures, congenital hip dysplasia, rheumatoid arthritis.). Outcome after revision TKA was less favorable than after primary TKA, particularly in case of painful knees with no other detectable anomaly. CONCLUSION: Surgical revision of TKA must follow a rigorous procedure with a detailed preoperative work-up. The decision for revision must not be made unless a precise anomaly has been identified.

Adult↗
PubMed1994

Evaluation of patellar tracking in patients with suspected patellar malalignment: cine MR imaging vs arthroscopy.

OBJECTIVE: The purpose of this study was to compare results of motion-triggered cine MR imaging of active extension of the knee with arthroscopic findings in cases of suspected femoropatellar malalignment. SUBJECTS AND METHODS: Twenty patients with clinically proved or suspected patellar subluxation or dislocation were examined prospectively with motion-triggered cine MR imaging to analyze patellar tracking from 30 degrees of flexion to full extension during active extension of the knee. The patellar tracking pattern was evaluated by measuring the following: bisect offset and lateral patellar displacement to assess lateralization of the patella and the patellar tilt angle to assess tilting of patella. The slopes of the linear regression lines of the MR findings vs the knee angle position, representing the patellar tracking, and the position of the patella at 30 degrees and 0 degrees of flexion were correlated with a semiquantitative arthroscopic classification of patellar tracking that had four categories ranging from normal to highly abnormal. RESULTS: The results showed a significant correlation between the semiquantitative arthroscopic findings of patellar tracking and the slopes of the linear regression lines of the bisect offset, lateral patellar displacement, and patellar tilt angle, as measured with cine MR imaging (p < .01). The arthroscopic findings also correlated significantly with the position of the patella when the knee was extended (p < .01), but not with the knee flexed 30 degrees. CONCLUSION: We conclude that motion-triggered cine MR imaging of active extension of the knee enables the dynamic evaluation of patellar bracing and is therefore suitable for noninvasive analysis of patellar tracking.

Adult↗
PubMed1978

Proximal tibiofibular joint: anatomic-pathologic-radiographic correlation.

An anatomic-pathologic-radiographic study of the proximal tibiofibular joint was undertaken. This synovial articulation between the proximal tibia and fibula may communicate with the knee joint in 10% of adults. Radiography of the normal proximal tibiofibular articulation outlines a consistent relationship between the proximal portions of the tibia and fibula. Disruption of this normal relationship is indicative of anterolateral or posteromedial subluxation or dislocation. Articular disorders of this joint include reheumatoid arthritis and septic arthritis. In the latter, initial alterations of the knee joint may subsequently extend to involve the proximal tibiofibular joint, illustrating the potential communication between these two articulations.

Arthritis, Rheumatoid↗
PubMed2003

Acute effects of hip and knee positions on motor-evoked potentials of the sciatic nerve in total hip arthroplasty.

In 23 patients, motor-evoked potentials (MEP) of the sciatic nerve were elicited during total hip arthroplasty by using a stimulating electrode at the level of the acetabulum and recording from the middle portion of the tibialis anterior. The distal motor latencies were determined before dislocation (control), during dislocation, and after reduction with the trial prosthesis. While the hip was dislocated, recording was performed at varying angles of the hip and knee joints. During dislocation, the distal motor latencies were significantly increased in all positions except at hip flexion of 60 degrees and internal rotation of 60 degrees with the knee joint in maximum flexion. No significant correlations were found between the latency increase and limb lengthening. No patient had sciatic nerve palsy or causalgia after operation.

Adult↗
PubMed1994

Acute patellar dislocation during eccentric muscle testing on the Biodex dynamometer.

Isokinetic training and muscle torque measurements are commonly used during rehabilitation after knee ligament injuries. Isokinetic maximal muscle strength tests are performed to monitor the progress in muscle rehabilitation. The muscle power is evaluated by measuring the applied force in the direction of motion (concentric muscle power) or the force against the direction of motion (eccentric muscle power). Both legs are examined to compare the total muscle work and peak torques of the involved leg with those of the uninvolved leg. We report the case of an acute patellar dislocation during eccentric testing of the uninvolved leg on the Biodex isokinetic dynamometer testing device (Biodex Corporation, Shirley, NY).

Acute Disease↗
PubMed1990

Scintigraphy in the assessment of anterior knee pain.

Sixty knees presenting with chronic anterior pain were investigated. A diffusely increased uptake indicated sympathetically mediated pain provided other diagnoses such as synovitis or widespread arthrosis were excluded. Focal uptake was not specific to any one condition, but could occur in chondromalacia patellae or recent dislocations. However, the commonest appearance found in chondromalacia patellae was a normal scan. A characteristic scintigraphic appearance in symptomatic postpatellectomy knees, which has not been previously reported, was increased uptake in the femoral groove. In all the cases where no clinical or arthroscopic diagnosis was made, the bone scan was normal. The use of radioisotope scintigraphy is recommended in the problem knee presenting with anterior pain.

Adolescent↗
PubMed1976

Occult traumatic dislocation of the patella.

In series of patients with clinically established traumatic patellar dislocation other authors have found surgical and radiological lesions pathognomonic for this condition. In a series of patients admitted with hemarthrosis, and with no knowledge of having had dislocation of their patella, we found the same lesions thus illustrating that a syndrome of occult traumatic patellar dislocation exists. The vertical location of the patients' patellae was found normal measured by the index of Insall and Salvati (9). The intercondylar groove measured by the method of Brattström (4) was found in almost all cases to be under the upper normal limit. Their knee caps were normal following the descriptions of Knutsson. None had valgus knees beyond normal upper limits and none had general laxity of joints, thus indicating that this syndrome may be found in normal knees.

Adolescent↗
PubMed1993

Scoring of patellofemoral disorders.

A new questionnaire was used to evaluate subjective symptoms and functional limitations in patellofemoral disorders. The questionnaire was completed independently by four groups of female subjects: controls (N = 17), and subjects with anterior knee pain (N = 16), patellar subluxation (N = 16), and patellar dislocation (N = 19). The questionnaire mean scores for the groups were 100, 83, 68, and 62 points, respectively (p < 0.0001). The items dealing with abnormal painful patellar movements (subluxations) (p < 0.0001), limp (p < 0.0001), pain (p < 0.0001), running (p < 0.0001), climbing stairs (p < 0.0001), and prolonged sitting with the knees flexed (p < 0.0001) differentiated the study groups most clearly. We recommend that these questions be asked when taking a standardized clinical history of an anterior knee pain patient. We also analyzed lateral patellar tilt and displacement by magnetic resonance imaging (MRI) in 28 subjects with patellar subluxation or dislocation. Low questionnaire sum score correlated best with increased lateral patellar tilt measured during quadriceps contraction in 0 degree knee flexion. It seems that a tendency to lateral patellar tilt during quadriceps contraction causes anterior knee pain and can be imaged in knee extension when the patella is not fully supported by femoral condyles.

Cartilage Diseases↗