Kenneth A. Krackow

Results of total knee arthroplasty after failed proximal tibial osteotomy for osteoarthritis

The cases of twenty-one consecutive patients who had a minimally constrained total knee arthroplasty (six of whom had a cemented and fifteen, an uncemented prosthesis) after a failed proximal tibial osteotomy for osteoarthritis were compared with those of a non-consecutive group of twenty-one patients who had had a primary total knee arthroplasty for osteoarthritis. The groups were matched according to age and sex of the patient, type of prosthesis and fixation, and length of follow-up. At an average length of follow-up of 2.9 years, a good or excellent result was obtained in 81 per cent of the patients who had had a previous osteotomy. At an average length of follow-up of 2.8 years, a good or excellent result was obtained in 100 per cent of the patients who had had a primary arthroplasty. Two patients in the osteotomy group and none in the primary arthroplasty group required additional surgery. At the time of arthroplasty, technical difficulties in exposing the proximal part of the tibia were noted in three patients in the group that had undergone an osteotomy. The results of total knee arthroplasty after failed proximal tibial osteotomy approached but did not equal the results after primary total knee arthroplasty.

Total joint arthroplasty of the knee.

The total knee experience at a hospital in Baltimore with the Universal Instruments and Total Condylar and Kinematic prostheses in 1978 and 1979, and with the PCA prosthesis with and without cement since 1980, has led to the development of the philosophy that impacts on all aspects of total knee arthroplasty. In most instances, if the patient is a suitable risk for surgery and symptoms are sufficiently disabling to justify knee fusion, the authors would first attempt a total knee arthroplasty regardless of age, weight, or other factors. Technical perfection of alignment and component position are their goals. The vast majority of total knee components can be mechanically fixed rigidly without the addition of methylmethacrylate. In general, clinical examinations (up to four years) suggest that the cementless results were equally as good as the cemented results and did not have a tendency to deteriorate with time.

Primary total knee arthroplasty in patients with fixed valgus deformity

Ninety-nine knees in 81 patients evaluated from two to ten years and having enough valgus deformity to require specific soft-tissue release were studied. They were also compared to a control group of 40 knees in 31 patients with no angular deformity greater than 5°, who were matched for age and diagnosis. All procedures were performed using a minimally constrained, posterior-cruciateligament-sparing prosthesis. Pre- and postoperative axial alignment was measured on weight-bearing long-standing roentgenographs. Analysis included examination for lucent lines in postoperative fluoroscopically positioned roentgenographs and clinical data summarized using the 100-point scoring systems developed by The Knee Society. Knees were classified as having Type I, II, or III valgus deformities: Type I was defined as valgus deformity secondary to bone loss in the lateral compartment and soft-tissue contracture with medial soft tissues intact; Type II was defined as obvious attenuation of the medial capsular ligament complex; and Type III was defined as severe valgus deformity with valgus malpositioning of the proximal tibial joint line after overcorrected proximal tibial osteotomy. Only cases of Type I and Type II were represented in the 99 knees reported. Type I patients were treated with lateral soft-tissue release, and Type II patients were treated with medial capsular ligament tightening (i.e., ligament reconstruction procedures on the medial side). The Knee Society postoperative knee score was 87.6 (10.6) and mean postoperative functional score was 52.3. Alignment was well corrected and knee scores for the Type I and II groups were almost identical as were the functional scores. The results were grouped as 72% excellent, 18% good, 7% fair, and 2% poor. Notably, the control group was 39 of 40 patients excellent, and only one poor. Ligament stability was satisfactorily established by lateral release in Type I and with the combined medial plication in the Type II patients. The ligament-tightening procedures were on the average 40 minutes longer than those for the Type I or the control groups. The controversial nature of the simultaneous ligament reconstruction method is recognized, but good experience is reported.

Osteotomy of the tibial tubercle during total knee replacement: a report of twenty-six cases

The cases of twenty-four patients who had twenty-six osteotomies of the tibial tubercle in conjunction with total knee replacement were analyzed with regard to complications and technical considerations. The patients were followed for a minimum of two years (average, three years and six months). Major complications related to the surgical technique occurred in 23 per cent of the knees and complications not related to the technique, in an additional 8 per cent. Rheumatoid arthritis and a history of at least one previous operation about the knee were predisposing factors for these complications.

Distal femoral varus osteotomy.

The results of twenty-three distal femoral varus osteotomies (in twenty-one patients) that were performed between 1977 and 1984 were evaluated. Fifteen osteotomies were done for osteoarthritis; three, for post-traumatic arthritis or deformity; three, for rheumatoid arthritis; and two, for renal osteodystrophy. The median age of the patients was fifty-six years (range, nineteen to seventy years). The length of follow-up averaged four years (range, two to nine years). The average tibiofemoral angle preoperatively was 18 degrees of valgus, which was corrected postoperatively to an average of 2 degrees of valgus. At follow-up, nineteen (83 per cent) of the twenty-three knees were rated as good or excellent according to The Hospital for Special Surgery knee score, which had improved from an average of 65 points preoperatively to 86 points post-operatively. Of the fifteen patients who had osteoarthritis (93 per cent), all but one had a good or excellent result. Most patients had no substantial improvement in the range of motion of the knee as a result of the operation. Eighty-six per cent of the patients expressed satisfaction with the outcome. We concluded that varus osteotomy of the distal part of the femur is a reliable and effective surgical procedure for the treatment of gonarthrosis associated with valgus deformity due to osteoarthritis or trauma. We do not recommend its use in patients who have rheumatoid arthritis or in those who have inadequate motion of the knee before the operation.

Ligament-tendon fixation: analysis of a new stitch and comparison with standard techniques

A newly devised locking loop tendon-ligament suture was evaluated for its clinical application. The suture is relatively simple to use and is particularly suited to flat structures such as the medial collateral ligament, joint capsule, and patellar tendon. It affects tension and resistance to pull out without exerting major purse stringing or bunching. In a laboratory setting, this suture technique has been compared to fixation by individual sutures and several varieties of staple fixation. Simple suture fixation was quite weak, measuring 100 newtons (N). Staple fixation is not only weaker than the ligament suture, but is more highly dependent on bone quality and is generally more variable. When employed with strong suture material, a doubled ligament suture was found to be nearly twice as strong (392 N) as staple fixation into bone (208 N) and demonstrated a mean pullout strength close to the forces observed on human anterior cruciate ligaments. In combination with a well placed ligament staple into good quality bone, fixation was further enhanced (482 N) and statistically significantly improved (P greater than .05).

A new technique for determining proper mechanical axis alignment during total knee arthroplasty: progress toward computer-assisted TKA.

Successful total knee arthroplasty (TKA) relies on proper positioning of prosthetic components to restore the mechanical axis of the lower extremity. This report presents and analyzes a new noninvasive method using the Optotrack (Northern Digital Inc, Ontario, Canada) to accurately determine the center of the femoral head. This method, together with direct digitization of the bony landmarks of the knee and ankle intraoperatively, permits placement of the lower extremity in proper alignment intraoperatively. It also permits the surgeon to follow all the angles of movement or rotation and all displacements that occur at each step of the operative procedure. knee intraoperatively via a customized Windows-based program. In addition to presenting our first case, which, importantly, represents the first computer-assisted TKA in a patient, we report on the accuracy and reproducibility of the technique for locating the center of the femoral head obtained during an extensive series of cadaver studies. Location of the femoral head, a major aspect of effecting neutral mechanical axis alignment, appears to be possible to within 2-4 mm, which corresponds to an angular accuracy of better than 1 degree. This method requires no computed tomography scans or other preliminary marker placement. The only basic requirement other than the instrumentation described is a freely mobile hip, which is generally present in TKA patients.

Corrective Osteotomy for Osteonecrosis of the Femoral Head. The Results of a Long-Term Follow-up Study*

We reviewed the long-term results of thirty-seven corrective osteotomies that had been performed for osteonecrosis of the femoral head that was stage II or III according to the classification of Ficat and Arlet. At a mean of 11.5 years (range, five to eighteen years) postoperatively, twenty-eight hips (76 per cent) had a good or excellent result according to the Harris hip-scoring system, and nine (24 per cent) had a fair or poor result and subsequently needed a total hip arthroplasty. Six of the nine failures were in the seventeen hips of patients who had received corticosteroids. Conversely, of the twenty hips of patients who had not received corticosteroids, seventeen (85 per cent) had a good or excellent result as determined by the Harris hip score at the latest follow-up evaluation. Five of the six hips that had had a combined necrotic angle of more than 200 degrees preoperatively had subsequent collapse of the femoral head. Of the thirty-one hips that had had a combined necrotic angle of less than 200 degrees preoperatively, twenty-seven (87 per cent) had a good or excellent clinical result. There were five complications. Three non-unions and one cutout of the compression screw were successfully treated, and these hips had an excellent clinical result at the time of the latest follow-up. The fifth complication was osteomyelitis and led to a poor result. The results of this study suggest that corrective intertrochanteric osteotomy is a successful treatment for Ficat and Arlet stage-II or III disease if the patient has a small or medium lesion (a combined necrotic angle of less than 200 degrees) and is not receiving continuous high doses of corticosteroids.

Flexion-extension joint gap changes after lateral structure release for valgus deformity correction in total knee arthroplasty: A cadaveric study

At the time of total knee arthroplasty, the surgeon generally corrects excessive valgus knee alignment to anatomic valgus through release of lateral supporting structures. This study used a cadaveric model to i) study the amount of correction achieved with each release step in 2 sequences of lateral release, ii) compare the amount of release in extension versus flexion, and iii) measure any associated rotational changes of the tibia. Six fresh-frozen cadaveric knees were used to test the amount of change into varus after sectioning the iliotibial band (ITB), the popliteus tendon (Pop), the lateral collateral ligament (LCL), and the tendon of the lateral head of the gastrocnemius (LG). This sequence was then compared with a second sequence in another 6 cadavers as follows: LCL, Pop, ITB, and LG. The amount of valgus correction was tested in 90 degrees, 45 degrees flexion, and full extension. At each flexion angle, the corresponding releases were assessed with the tibia oriented vertically under its own weight, under tibial distraction with equal support from the lateral and medial soft tissues, and under a maximal varus deforming stress. Results showed that complete lateral structure release provides limited correction into a varus direction with a balanced distracted soft tissue gap or extension space (8.9 degrees with the LG released), and the lateral aspect of the flexion gap opens more than the extension gap (8.9 degrees compared with 18.1 degrees in flexion). Early LCL release provided a more uniform release of the joint gap, and rotational changes were variable, tending toward external rotation of the tibia (6.0 degrees in full extension with release of the LCL). We suggest that when severe valgus deformities are present, the LCL should be considered first for release and the Pop and ITB be used to grade the release.

The Operative Treatment of Peroneal Nerve Palsy

We retrospectively reviewed the results of operative decompression for peroneal nerve palsy in thirty-one patients who had been managed between 1980 and 1990. All patients had been managed non-operatively for at least two months after they had initially been seen. Intraoperatively, we found epineurial fibrosis and bands of fibrous tissue constricting the peroneal nerve at the level of the fibular head and at the proximal origin of the peroneus longus muscle. At a mean of thirty-six months (range, twelve to seventy-two months) postoperatively, thirty (97 per cent) of the thirty-one patients reported subjective and functional improvement and were able to discontinue the use of the ankle-foot orthosis. In contrast, only three of nine patients who had been managed non-operatively reported subjective and functional improvement (p < 0.01). Peroneal nerve palsy does not always resolve spontaneously; if it is left untreated, the loss of dorsiflexion of the ankle and persistent paresthesias can result in severe functional disability. Therefore, if non-operative measures do not lead to improvement within two months, we believe that operative decompression should be considered.