Proximal tibial osteotomy. A critical long-term study of eighty-seven cases

Avoidance of medial cortical fracture in high tibial osteotomy: improved technique

A new technique in oblique incomplete high tibial osteotomy that permits an increase of valgus correction while preventing fracture of the medial cortex was investigated. Closing wedge or opening wedge osteotomy was done on 23 tibias from cadavers before loading in an Instron testing machine. In seven specimens (Group 1), lateral oblique wedge osteotomy was done. In seven other specimens (Group 2), one medial oblique cut was made. In both groups, the osteotomy terminated 10 mm from the cortex and approximately 2 cm below the plateau. In nine specimens (Group 3), the osteotomy terminated in a 5-mm diameter hole, drilled in an anteroposterior direction, with its center positioned 10 mm from the medial cortex and 2 cm below the articular surface. The maximum angle of opening or closing before fracture of the cortex took place was recorded. In Groups 1 and 2, similar maximum correction angles were observed, 6.7 degrees versus 6.5 degrees, respectively. In Group 3, the stress relieving hole allowed the correction angle to be increased to 10 degrees. An oblique high tibial valgus closing wedge osteotomy with an apical drill hole allows a significant increase of the correction angle compared with the same osteotomy without a drill hole. Medial open wedge osteotomy offers no advantage over lateral closed wedge osteotomy in the maximum obtainable correction angle without failure of the cortex.

Surgical approaches for osteoarthritis

Patients with osteoarthritis (OA) often benefit from properly performed surgical procedures. However, the scientific database from studies investigating appropriate timing of surgery, patient morbidity, quality of life before and after the intervention, and cost utility of different procedures is insufficient. In order to allow a fair allocation of resources in future health care systems, randomized controlled trials (RCTs) with defined entry criteria, sufficient number of patients, and valid outcome measures should be performed for different surgical approaches. They should especially include control groups with conservative treatment in order to allow an evidence based comparison between different therapeutic approaches. At present, however, optimal management of OA as a dynamic disease process must include a combination of conservative as well as operative treatment modalities. In case of malalignment, instability and intra-articular causes of mechanical dysfunction, correction of these abnormalities and relief of symptoms can be achieved with properly indicated and performed osteotomies. Debridement by arthroscopy and arthotomy probably does not alter the natural history of OA and true clinical outcomes are difficult to determine, but it can provide transient relief of symptoms. Joint replacement has to be considered for refractory pain associated with disability and radiological deterioration. As the pre-operative functional status seems to influence the outcome not only in joint replacement but also in joint-preserving osteotomies, the indication for these procedures might be expanded in the future.

High tibial osteotomy versus unicompartmental joint replacement in unicompartmental knee joint osteoarthritis: 7-10-year follow-up prospective randomised study

The clinical outcome of patients treated either by high tibial osteotomy or unicompartmental arthroplasty for medial unicompartmental osteoarthritis of the knee was compared in a prospective randomised study. In total, 32 patients received a high tibial osteotomy (HTO) and 28 patients a unicompartmental arthroplasty (UKA). More intra- and postoperative complications were observed after HTO. Patients were assessed at an average of 2.5 (1.6-5), 4.5 (3.6-7), and 7.5 years (6.6-10) after the operation. Using the Knee Society Score, 71% (15) of patients after osteotomy and 65% (13) after replacement had a knee score of excellent or good 7-10 years postoperatively. The Kaplan-Meier survival analysis 7-10 years postoperatively showed a survivorship of 77% for UKA and 60% for HTO. Although the unicompartmental prosthesis used in this series has not shown promising results, we conclude that with the advanced design of unicompartmental prosthesis today, UKA offers better long-term success.

Open wedge tibial osteotomy with acrylic bone cement as bone substitute

We studied the results of 245 valgus producing high tibial osteotomies performed with the use of an opening wedge technique and rigid internal fixation followed by early passive and active motion of the knee. Previous studies have used iliac bone grafts or hemicollastasis held by an external fixator for opening the osteotomy. In our series the opening was obtained by a block of cement interposed in the postero-medial part of the osteotomy. This series confirms that the opening wedge osteotomy allows good accuracy for the correction. Ninety-three percent of the knees had a correction adjusted between 180 and 187 degrees for the hip-knee-ankle angle. Survivorship analysis showed an expected rate of survival, with conversion to a total knee on the end point, of 94% at 5 years, 85% at 10 years and 68% at 15 years. Conversion to a total knee arthroplasty was accomplished without difficulty in the patients who had this procedure done. We recommend opening wedge tibial osteotomy with acrylic cement bone cement as bone substitute, rigid internal fixation, and early motion for patients who undergo high tibial osteotomy.

Minimally invasive selective osteotomy of the knee: A new surgical technique

We present a simple surgical technique created by the authors to address degenerative chondral lesions of the knee and its application in a limited prospective case series. The technique assumes the concept of beneficial epiphyseal changes caused by disruption of the subchondral bone in improving symptoms, as with drilling, microfracture, periarticular osteotomy, and other invasive procedures. Minimally invasive selective osteotomy (MISO) is an expansion of the arthroscopic treatment of the knee, specifically targeting symptomatic lesions with minimal additional trauma and cost, while avoiding disruption of the articular surface of the subchondral bone. The technique involves a mimimal access approach with selective saw cuts placed with a 1-cm oscillating blade parallel to the joint surface 1 to 1.5 cm deep to identified lesions. The technique does not address malalignment but can address lesions not addressed by classic osteotomies and, as such, may be combined with other corrective alignment procedures as necessary. We present the results of MISO of the knee in a case series of 62 outpatients carried out at the Orthopaedic Division of the Clinical and Surgical Hermanos Ameijeiras Hospital in Havana, Cuba. At 2-year follow-up, there was improvement of symptoms without significant complications.

Preoperative planning for lower extremity osteotomies: an analysis using 4 different methods and 3 different osteotomy techniques

Lower extremity osteotomy is a common procedure for managing deformity and unicompartmental gonarthrosis. One consideration not typically addressed is how the osteotomy will affect the leg length of the extremity. This article presents a numerical analysis of apparent leg-length change before and after osteotomy surgery. It also compares the differences resulting from the 3 different major types of osteotomies (closing wedge, opening wedge, and dome). Three different preoperative planning methods and a fourth intraoperative technique were studied. Using different methods of preoperative planning with the same osteotomy technique resulted in leg-length changes of 0.5 to 3 mm. Differences > 7 degrees in lower extremity alignment may result depending on the planning method used. When comparing osteotomy techniques, 2 cm in leg-length difference was calculated.

Patellar infera after high tibial osteotomy

Forty-six knees in 41 patients that had undergone high tibial osteotomy (HTO) were evaluated to assess the potential correlation between alteration in the inclination of the proximal tibial articular surface and subsequent patellar height. Of the knees examined, 61% lost > or =5 degrees of posterior tibial inclination after HTO, whereas 54% of knees showed a relative lowering of patellar height of >10%, as measured by the Insall-Salvati ratio. The loss of the normal posterior tibial inclination was found to have a statistically significant association with the subsequent loss of the patellar height. Clinically, these results suggest that careful preservation of the posterior tibial inclination at the time of HTO could minimize the risk of subsequent patellar infera and alteration in patellofemoral mechanics.

High tibial osteotomy using a dynamic axial external fixator

High tibial osteotomy is an accepted treatment for unicompartmental osteoarthritis of the knee. Conventional osteotomy can be a demanding procedure with potential for complications. Opening wedge high tibial osteotomy using an external fixator is an alternative that may have advantages in comparison with classic methods. The aims of the current study were to determine if opening wedge osteotomy using hemicallotasis techniques is safer than, and the outcome comparable with that of, conventional techniques. Seventy-six high tibial osteotomies were performed in 65 patients for primary osteoarthritis. The mean age of the patients was 54.8 years (range, 36-70 years). The mean followup was 6 years. The only serious complication occurred in one patient, who had chronic osteomyelitis develop 2 years after surgery. There were no neurologic or vascular complications. The authors think this technique is safer than conventional techniques. Survivorship at 5 and 10 years was 89% and 63%, respectively. The mean knee score in osteotomies was 26.6 (maximum possible score, 48). The outcome is comparable with, or better than, that of other techniques for osteotomy. Subsequent knee replacement, in cases requiring conversion, was straightforward. The mean score in knees that had osteotomies that were converted to total knee replacements was 33.7.

Progression of joint arthrosis 10 to 15 years after high tibial osteotomy

Forty-eight knees in 44 patients who had a high tibial osteotomy performed for medial compartment osteoarthritis were reevaluated twice, once at 1 year after surgery and again at 10 to 15 years after the high tibial osteotomy, to determine the effects of high tibial osteotomy on progression of medial and lateral joint arthrosis. Radiologically, although arthrosis significantly increased in the medial and the lateral joint compartment, there was no significant difference in the degree of progression between the two compartments. There was a significant correlation between the progression of medial joint arthrosis evaluated at 10 years or more after surgery and the femorotibial angle measured at 1 year. There was no significant correlation between the progression of lateral joint arthrosis in 10 to 15 years and the femorotibial angle measured at 1 year. The average knee function score improved significantly from 59.1 +/- 5.5 points before surgery to 85.1 +/- 6.1 points at the 1-year followup. At the final followup, the clinical score (80.7 +/- 5.4) had deteriorated relative to the 1-year results but still was significantly better than the preoperative score. The current results indicate that the greater the surgical valgus correction, the slower the progression of medial joint arthrosis. Lateral joint arthrosis did not progress more quickly after high tibial osteotomy, even if an overcorrection was performed.

High tibial osteotomy without internal fixation for medial unicompartmental osteoarthrosis

Between 1982 and 1993, a total of 35 patients underwent high tibial osteotomy for medial unicompartmental osteoarthrosis. The osteotomy was performed high in the tibia without the use of jigs, and internal fixation devices were avoided. Patients were assessed using the British Association for Surgery of the Knee score, and satisfactory results with minimal complications were obtained. Our results indicate that in a select group of patients, high tibial osteotomy preserves bone stock and is performed near the deformity so that excellent correction is achieved and recurrence of varus deformity is avoided.

Total knee arthroplasty after high tibial osteotomy. A comparison study in patients who had bilateral total knee replacement

BACKGROUND

The outcome of total knee replacement after high tibial osteotomy remains uncertain. We hypothesized that the results of total knee replacement with or without a previous high tibial osteotomy are similar.

METHODS

The results of a consecutive series of thirty-nine bilateral total knee arthroplasties performed with cement at an average of 8.7 years after unilateral high tibial osteotomy were reviewed. There were twenty-seven men and twelve women. Preoperatively, the knee scores according to the system of the Knee Society were similar for all of the knees; however, valgus alignment and patella infera were more common in the knees with a previous high tibial osteotomy. Bilateral total knee replacement was staged in seven patients and was simultaneous in thirty-two patients. The results of the total knee arthroplasties were retrospectively reviewed with respect to the knee and function scores according to the system of the Knee Society, the radiographic findings, and the complications.

RESULTS

Intraoperatively, no notable differences were identified in the number of medial, lateral, or lateral patellar releases required. However, less lateral tibial bone was resected in the group with a previous high tibial osteotomy (average, 3.3 millimeters) than in the group without a high tibial osteotomy (average, 7.5 millimeters). The average duration of follow-up was 7.5 years (range, three to sixteen years) in the group with a previous high tibial osteotomy and 6.8 years (range, two to ten years) in the group without a high tibial osteotomy. At the time of the final follow-up, the knee and function scores were similar for the two groups (89.0 and 81.0 points, respectively, for the group with a previous high tibial osteotomy, and 89.6 and 83.9 points, respectively, for the group without a high tibial osteotomy). Although more knees were free of pain in the group without a previous high tibial osteotomy (thirty-six) than in the group with a previous osteotomy (thirty-three), this difference was not found to be significant with the numbers available (p = 0.4810). Knee alignment and stability, femoral and tibial component alignment, and range of motion also were similar in both groups postoperatively. One allpolyethylene tibial component was revised in the high tibial osteotomy group. Two knees in each group required manipulation. There were no deep infections.

CONCLUSIONS

While patients with a previous high tibial osteotomy may have important differences preoperatively, including valgus alignment, patella infera, and decreased bone stock in the proximal part of the tibia, the present study suggests that the clinical and radiographic results of primary total knee arthroplasty in knees with and without a previous high tibial osteotomy are not substantially different. In our relatively small group of patients, the previous high tibial osteotomy had no adverse effect on the outcome of the subsequent total knee replacement.

Management of unicompartmental arthritis in the anterior cruciate ligament-deficient knee

There exists a group of patients who are difficult to manage because they have both anterior knee instability secondary to anterior cruciate ligament deficiency and unilateral degenerative joint disease. A large majority of these patients report a history of previous meniscal injury or meniscectomy after knee trauma at a relatively young age. Active patients who report symptomatic knee instability or pain associated with athletics or activities of daily living after conservative treatment may be indicated for surgery. Current endoscopic methods of anterior cruciate ligament reconstruction result in low patient morbidity, the elimination of anterior knee instability, and a timely return of function. Osteotomies about the knee joint are an effective means of treating unicompartmental knee arthrosis. Long-term studies have demonstrated that knee osteotomy is a good surgical option for patients with unicompartmental arthritis who are considered too young for total knee arthroplasty. We describe a comprehensive treatment approach to the patient with anterior cruciate ligament deficiency and isolated medial or lateral osteoarthritis. An assessment of pain symptoms, instability symptoms, and lower extremity alignment is used to formulate a treatment plan.

Total knee arthroplasty after high tibial osteotomy

Between 1980 and 1995, 95 consecutive total knee replacements were performed at an average of 10 years 4 months after high tibial osteotomy. The average age of the 82 patients was 66 years, with a preoperative diagnosis of osteoarthritis in 94 knees. One patient died 6 months after surgery. The followup of the remaining 81 patients (94 knees) averaged 8.6 years (range, 2-17 years). Knee Society knee score at final followup improved to an average of 87.6 points from a preoperative average of 38.1 points. No pain was present in 86.2% of knees, and 12.8% of knees had only mild or occasional pain. Tibial radiolucencies were identified in 12 (12.8%) knees at final followup, and in only four knees were radiolucent lines found about the lateral zones. Only one tibial component required revision 3 years after surgery. Although no preoperative factor was identified that predisposed to an inferior knee score, function score, or pain score, the severity of the preoperative flexion contracture and the number of previous surgeries did relate to diminished postoperative motion. However, an increased number of patellar radiolucencies were seen in the knees in which the lateral joint line was raised (referenced from the fibular head) a greater degree. The clinical results of total knee replacement after high tibial osteotomy appeared similar to those of primary total knee replacement. The previous high tibial osteotomy had no adverse effect on the eventual results of a cemented posterior cruciate retaining total knee replacement.

High tibial osteotomy with a calibrated osteotomy guide, rigid internal fixation, and early motion. Long-term follow-up

BACKGROUND

We studied the results of sixty-four valgus-producing high tibial osteotomies performed with the use of a calibrated osteotomy cutting guide and rigid internal fixation, and followed by early motion, in fifty-six patients who had medial unicompartmental osteoarthritis and varus malalignment. Long-term studies have demonstrated that a high tibial osteotomy performed with staple fixation and followed by immobilization in a cast has an expected survival rate of approximately 85 percent at five years and 60 percent at ten years (in studies of ninety-five knees and 213 knees, respectively). To the best of our knowledge, there are no long-term reports on high tibial osteotomies performed with a calibrated osteotomy cutting guide and rigid internal fixation and followed by early motion.

METHODS

The indications for high tibial osteotomy were medial unicompartmental osteoarthritis and varus malalignment. A lateral closing-wedge osteotomy was performed. The patients were reexamined to obtain a knee score, to make lateral radiographs of both knees, and to make a full-length anteroposterior radiograph (showing the entire lower extremity, including the hip and ankle) of the involved knee with the patient standing.

RESULTS

Twenty-one knees were treated with a subsequent total knee arthroplasty at an average of sixty-five months after the high tibial osteotomy. The remaining forty-three knees had a good or excellent clinical result, with an average knee score of 94 points at an average of 8.5 years after the osteotomy. Survivorship analysis showed an expected rate of survival, with conversion to a total knee arthroplasty as the end point, of 85 percent at five years and 53 percent at ten years. No patient had patella baja postoperatively. There were six complications: four superficial wound infections, one superficial-vein thrombosis, and one delayed union (union occurred at five months).

CONCLUSIONS

High tibial osteotomy has been criticized because of a high rate of complications, a loss of effectiveness with time, and the difficulty of conversion to a total knee arthroplasty secondary to patella baja. In our series, in which an osteotomy was performed with a calibrated osteotomy cutting guide and rigid internal fixation and was followed by early motion, the rate of complications was low and approximately two-thirds of the knees had a good or excellent clinical result at an average of 8.5 years. Conversion to a total knee arthroplasty was accomplished without difficulty in the patients who had this procedure. We highly recommend high tibial osteotomy with a calibrated osteotomy cutting guide, rigid internal fixation, and early motion for patients who wish to continue an active lifestyle.

Changes in osseous correction after proximal tibial osteotomy: radiostereometry of closed- and open-wedge osteotomy in 33 patients

33 patients (22 men), median age 54 (40-68) years, with medial gonarthrosis grades 1-3, were treated by closed-wedge osteotomy (high tibial osteotomy = HTO, n 16) or open-wedge osteotomy by hemicallotasis (hemicallotasis osteotomy = HCO, n 19). 2 patients were operated on bilaterally. The patients were studied by RSA (radiostereometric analysis) for measuring 3-D changes in the correction achieved. In the HTO group the RSA measurements were obtained at the time of plaster removal, 1 month later and 1 year after surgery. In the HCO group, the RSA measurements were performed at the time of removal of the external fixator, 1 month later and 1 year after surgery. After removal of the fixation, HTO was associated with increased medial/lateral and distal translation of the proximal segment, compared to HCO. In addition, the tibial plateau rotated more around the longitudinal axis of the tibia after HTO.

Progressive opening-wedge osteotomy for severe tibia vara in adults

Five patients with tibia vara were treated with progressive opening-wedge osteotomy. The maximum varus deviation of the mechanical axis of the tibia varied from 20 degrees to 12 degrees. The minimum postoperative follow-up was 26 months. Complete correction of the deformity was achieved without any major complications. Progressive opening-wedge osteotomy offers several advantages over conventional osteotomy in adults. First, fibular osteotomy is unnecessary. Second, knee mobility is only slightly restricted immediately following surgery. Third, it is possible to adjust correction postoperatively, and finally, progressive opening-wedge osteotomy does not induce shortening of the lower limb. The most significant disadvantage is the need for prolonged external fixation. This technique should be reserved for patients with severe deformities (minimum of 15 degrees varus) and mild or moderate osteoarthrosis.

Total knee replacement after failed tibial osteotomy: results of a matched-pair study

Sixty-three total knee replacements were performed after a failed tibial osteotomy. The goal of this study was to compare the perioperative problems and the outcome of this group of patients (study group) to a group of patients with primary arthroplasties matched for age, gender, length of follow-up, weight, and preoperative Charnley class. Operative problems were more frequently encountered in the study group, with 7 tibial tubercle elevations and 15 lateral retinaculum releases needed, whereas lateral retinaculum release was necessary for only 1 knee in the control group. Outcome was assessed using both the International Knee Society (IKS) scoring system and Hospital for Special Surgery (HSS) knee score. The follow-up period averaged 4.6 years. The IKS score of the control group was significantly higher, averaging 80.9 +/- 13.8, whereas it was 74.4 +/- 14.8 for the study group (P = .0001). Among the parameters included in the knee score, only pain was significantly different with the control group (P = .03). The IKS function score and the HSS score were not statistically different. Conversion of a failed tibial osteotomy is a technically demanding procedure. Careful preoperative planning is needed. Results, especially on pain, appeared to be inferior to those for primary arthroplasties.

Total knee arthroplasty in patients 55 years old or younger. 10- to 17-year results

Seventy-four consecutive total knee arthroplasties in 54 patients who were 55 years of age or younger (average age 43 years) were reviewed. All patients had a minimum followup of 10 years with an average followup of 13 years (range, 10-17 years). No patients died or were lost to followup. The preoperative diagnosis was rheumatoid arthritis in 47, gonarthrosis in 12, posttraumatic arthritis in six, osteonecrosis in three, hemophilia in two, and one patient each with pigmented villonodular synovitis, tuberculosis, systemic lupus erythematosus, and achondroplasia. The knee score improved from an average of 36 points (range, 10-80 points) preoperatively to 84 points (range, 37-100 points) at latest followup. The functional score improved from 45 points (range, 0-100 points) to 60 points (range, 0-100 points) at latest followup. Two patients had their implants revised: one at 3 years because of ligamentous laxity and one at 13 years because of aseptic loosening of the tibial component. There were no deep infections. There were no radiographically loose implants at latest followup. The implant survival to revision at 10 years was estimated at 99% (confidence limit, 96%-100%). The implant survival to revision at 15 years was estimated at 95% confidence limit, 88%-100%). Cemented total knee arthroplasty in the young patient is a reliable procedure and has excellent results at 13-year followup with an estimated survivorship of 99% at 10 years.

Treatment of articular cartilage defects of the knee with autologous chondrocyte implantation

The treatment of focal full thickness articular defects in the knee has continued to present a challenge, with no traditional treatment method providing consistent acceptable long-term clinical results. Patients with significant chondral defects frequently have persistent joint line pain, swelling, and catching in the knee. In contrast to marrow stimulation treatment techniques, such as abrasion arthroplasty, drilling, or microfracture which populate the defect with pluripotential stem cells, the use of cultured autologous chondrocytes fills the defect with cells of a committed pathway to develop hyaline-like cartilage. This hyaline-like cartilage more closely recreates the wear characteristics and durability of normal hyaline cartilage than the fibrous or fibrocartilage repair tissue formed by pluripotential stem cells. The purpose of this paper is to review the efficacy of available treatment options as well as the basic science rationale, indications, technique, postoperative rehabilitation, and clinical results of using cultured autologous chondrocytes in the treatment of focal full thickness chondral defects of the knee.

Patella height after high tibial osteotomy with internal fixation and early motion

The purpose of this study was to compare the incidence of patella infera in patients after high tibial osteotomy treated with either postoperative immobilization or internal fixation and early range of motion. A retrospective review of 98 patients with high tibial osteotomy was done at the authors' institution. Thirty-three patients who had secondary procedures such as concomitant ligamentous reconstruction with early motion were excluded. Therefore, 69 knees in 65 patients remained in the study cohort. Group A consisted of 32 patients (34 knees) treated with postoperative immobilization, whereas Group B included 33 patients (35 knees) treated with internal fixation and early motion. The preoperative and postoperative Insall-Salvati index, Blackburne-Peel index, and angular alignment were determined for each group. Between Groups A and B, the differences in the Insall-Salvati index and the Blackburne-Peel index were statistically significant, although the difference in angular correction was not significant. With rigid fixation and early motion the Insall-Salvati index showed that there was less postoperative shortening of the patellar tendon. The relationship of the patella to the remainder of the knee was affected less adversely as evidenced by the Blackburne-Peel index. High tibial osteotomy with internal fixation and early range of motion should result in a better knee and ease the subsequent performance of a total knee arthroplasty.

Knee arthritis in active individuals: matching treatment to the diagnosis

Even among the active middle-aged population, knee arthritis is a common condition that can greatly decrease quality of life. The 45 degrees flexion weight-bearing radiograph, a crucial diagnostic step, can show joint space loss. Each patient must be treated individually, but conservative treatment with medication, activity modification, exercise, physical therapy, braces, and joint injections may be effective for long periods. Operative modalities include joint arthroscopy and reconstructive procedures such as osteotomy and joint arthroplasty. In injured knees, meniscus and cartilage transplants may prevent the development or progression of osteoarthritis. Total knee arthroplasty should be considered in active patients only when all other options have been exhausted.

Open wedge tibial osteotomy by callus distraction in gonarthrosis. Operative technique and early results in 36 patients

Proximal tibial osteotomy is indicated in cases of medial gonarthrosis with varus deformity in the active, younger patient. We report our experience of the hemicallotasis technique in 36 patients and the early clinical results after a median follow-up of 14 (11-16) months. The median patient age was 54 (33-64) years. The median hip-knee-ankle (HKA) angle was 172 (161-179) degrees preoperatively, 184 (178-187) degrees after completed correction and 183 (175-190) degrees at follow-up. The median fixation time was 88 (61-146) days. Complications were minor. Superficial pin-site inflammation/infections occurred in one fifth of the pins. The HSS score increased from a median 71 preoperatively to 94 at follow-up, the Lysholm score from 56 to 91 and the Tegner activity score from 6 to 10. The Nottingham Health Profile showed significant improvements as regards pain and physical mobility.

Articular cartilage repair

Articular cartilage can tolerate a tremendous amount of intensive and repetitive physical stress. However, it manifests a striking inability to heal even the most minor injury. Both the remarkable functional characteristics and the healing limitations reflect the intricacies of its structure and biology. Cartilage is composed of chondrocytes embedded within an extracellular matrix of collagens, proteoglycans, and noncollagenous proteins. Together, these substances maintain the proper amount of water within the matrix, which confers its unique mechanical properties. The structure and composition of articular cartilage varies three-dimensionally, according to its distance from the surface and in relation to the distance from the cells. The stringent structural and biological requirements imply that any tissue capable of successful repair or replacement of damaged articular cartilage should be similarly constituted. The response of cartilage to injury differs from that of other tissues because of its avascularity, the immobility of chondrocytes, and the limited ability of mature chondrocytes to proliferate and alter their synthetic patterns. Therapeutic efforts have focused on bringing in new cells capable of chondrogenesis, and facilitating access to the vascular system. This review presents the basic science background and clinical experience with many of these methods and information on synthetic implants and biological adhesives. Although there are many exciting avenues of study that warrant enthusiasm, many questions remain. These issues need to be addressed by careful basic science investigations and both short- and long-term clinical trials using controlled, prospective, randomized study design.

Time-dependent clinical and roentgenographical results of Coventry high tibial valgisation osteotomy

We analyzed the time-dependent results after Coventry osteotomy in 118 patients (129 cases) with uni-compartmental osteoarthrosis of the knee. The median follow-up was 11.6 years (range 0.7-17 years). Data were noted according to the time since surgery. Group I (> 2 years) consisted of all 129 cases, group II (> 4 years) of 41 cases and group III (> 8 years) of 15 cases. The HSS knee score (max. 100 points) improved from 33.2 +/- 20.4 (range 17-60) to 68.3 +/- 25.3 (range 30-90) in group I, to 54.7 +/- 18.9 (range 29-90) in group II and to 43.7 +/- 20.9 (range 23-85) in group III. The improvement started 4.6 +/- 7.8 months (range 0-60 months) after the operation and persisted for 4 years +/- 37.4 months (range 0-125 months). The functional knee score (max. 100 points) changed from 61.7 +/- 14.1 (range 41-70) to 71.7 +/- 13.1 (range 53-87) in group I, to 70.0 +/- 11.8 (range 54-88) in group II and to 64.2 +/- 8.0 (range 42-90) in group III. The initial loss in knee flexion was 5.6 degrees (range 0 degree-20 degrees) and for extension 1.0 degree (range -5 degrees-25 degrees). Anteroposterior ligament stability (max. 10 points) decreased from 9.2 +/- 2.1 (range 2-10) to 5.6 +/- 1.7 (range 2-9) in group III. Lateral ligament stability (max. 15 points) was relatively constant, from 12.6 +/- 1.9 (range 4-15) to 9.7 +/- 1.9 (range 2-14). Complications included one tibia fracture, one infection, six peroneus pareses, four haematomas and one pseudarthrosis. The mechanical axis was corrected to an average knee valgu2 of 5.2 degrees +/- 7.4 degrees, which deteriorated over time. Radiographic evidence of arthrosis appeared independent of the operation.

Effects of medial and lateral displacement calcaneal osteotomies on tibiotalar joint contact stresses

Translational calcaneal osteotomies are used clinically to realign the mechanical axis of the lower limb. In this study, the effects of medial and lateral displacements of the posteroinferior fragment on tibiotalar joint contact mechanics were assessed using pressure-sensitive film. Eight osteotomized fresh-frozen cadaver specimens were loaded in each of three testing positions: neutral position (no shift), 1 cm of lateral displacement of the inferior fragment with respect to the superior fragment, and 1 cm of medial displacement of the inferior fragment. For an applied load of 1,330 N, two times body weight, a 1 cm lateral displacement shifted the center of pressure an average of 1.06 mm laterally, whereas a 1 cm medial displacement shifted the center of pressure an average of 1.58 mm medially. While global contact parameters (contact area, spatial mean contact stress, and peak local contact stress) were not appreciably altered by osteotomy, regional contact parameters changed in a reproducible and statistically significant manner. Among four nominally equal-sized, parasagittally bounded cartilage zones, lateral displacements consistently unloaded the most medial zone and increased loading of the most lateral zone; medial calcaneal displacements had the converse effect. These cadaver results suggest that translational calcaneal osteotomies may be used clinically to partially offload focal areas of cartilage along the medial and lateral borders of the tibiotalar joint.

Participation in sports after hip and knee arthroplasty: review of literature and survey of surgeon preferences

OBJECTIVE

To summarize previously published findings and to present the opinions of a group of reconstructive orthopedic surgeons from a single institution on participation in sports after hip or knee arthroplasty.

DESIGN

We reviewed the literature pertaining to participation in sports after hip or knee arthroplasty and surveyed a group of orthopedic surgeons about their recommendations for resumption of various sports activities by patients who had undergone total hip or knee arthroplasty.

MATERIAL AND METHODS

A computerized literature search was performed, and salient issues about participation in sports after joint replacement procedures were synthesized. At the Mayo Clinic, 28 orthopedic surgeons (13 consultants and 15 fellows or residents) completed a single-page questionnaire that requested a recommendation ("yes," "no," or "depends") about patients resuming participation in 28 common sports after recovery from total hip or knee arthroplasty. Staff surgeon responses were compared with responses from fellows and residents by using the Mann-Whitney U test. Sports in which 75% of surgeons would not allow participation were identified as "not recommended," whereas sports in which 75% of surgeons would allow participation were labeled as "recommended."

RESULTS

Fellows and residents were less likely than staff surgeons to allow return to cross-country skiing after total knee arthroplasty. Otherwise, responses from consultant surgeons and from fellows and residents did not differ significantly. Recommended sports included sailing, swimming laps, scuba diving, cycling, golfing, and bowling after hip and knee replacement procedures and also cross-country skiing after knee arthroplasty. Sports not recommended after hip or knee arthroplasty were running, waterskiing, football, baseball, basketball, hockey, handball, karate, soccer, and racquetball.

CONCLUSION

After hip or knee arthroplasty, participation in no-impact or low-impact sports can be encouraged, but participation in high-impact sports should be prohibited.

Anterior cruciate ligament reconstruction combined with valgus tibial osteotomy (combined procedure)

We assessed the patients who were operated on in a combined procedure from 1980 to 1992 with anterior cruciate ligament (ACL) insufficiency, cartilaginous lesions of the medial compartment, lesion of medial meniscus and varus malalignment. The combined operative procedure was autologous intra-articular ACL reconstruction with the middle third of the patellar ligament--partially augmented with Kennedy-ligament augmentation device (LAD) in hot dog technique--and high tibial osteotomy. The patients were examined according to the criteria of IKDC including testing of anterior stability with the KT-1000 arthrometer. Radiographically we checked axis and arthritis according to a modified score of Kannus. Twenty-seven of 34 patients who fulfilled the inclusion criteria could be followed up in three categories (2-5 years post-operatively, 5-10 years postoperatively, over 10 years post-operatively). Total qualification was good in 37%; there were no perioperative complications. Rehabilitation was not prolonged. Eighty-nine percent practised their preoperative job, over 50% had a higher level of sports activities than preoperatively, and more than 25% regained their pretraumatic sports capacity. Two-thirds had no giving way and less than 3 mm translation difference in comparison to the contralateral knee. Seventy-five percent of patients would accept the operation again. Radiological findings had no correlation to overall qualification. The encouraging results with respect to many of the criteria suggest using the combined procedure in a young patient with ACL insufficiency, varus malalignment and medial compartment damage including medial meniscus lesion.