[Total knee arthroplasty by lateral parapatellar approach for valgus knee].

OBJECTIVE: To investigate the effect of lateral parapatellar approach in total knee arthroplasty (TKA) of valgus knee. METHODS: Lateral parapatellar approach of total knee arthroplasty was applied in 8 patients (10 knees) with severe valgus osteoarthritis knee (bilateral in 2 cases and unilateral in 6 cases), with the valgus angle > 15 degrees , 1 male (1 knee) and 7 females (9 knee), aged 68.2 (58 - 79), 7 cases (9 knees) being of the Krackow type I and 1 case (1 knee) of the Krackow type I, I. After incision of the skin through lateral knee, ilio-tibial band was prolonged by apple pie arthroplasty. The joint capsule was cut open laterally 2 - 4 cm from the para-patellar edge. Soft tissue balance was performed by releasing I - T band in Gerdy tubercle, lateral collateral ligament and poster-lateral capsule from the femur and tibial side. Valgus angle of distal femur cutting were five degree. Whiteside line and trans-epicondylar line were used as AP rotational cutting reference. All patellar of the group were resurfaced. Capsule closure is completed with the knee flexed. The expanded deep lateral soft tissue sleeve (coronal Z-plasty) is sutured with the medial retinaculum sleeve (superficial layer). Follow-up was conducted for 19.6 months (1 - 51 months). RESULTS: Seven cases (9 knees) were replaced by posterior stabilized cemented prostheses (TC-Dynamic, PLUS), one case (1 knee) was replaced by RT prosthesis (RT-PLUS(TM) Solution, PLUS). After operation, the valgus deformity of all patients was corrected and all patients could walk 100 m with or without the help of walking holders. The average range of motion (ROM) was improved from the pre-operative. 95.6 degrees (85 degrees - 110 degrees ) to the post-operative 117.1 degrees (100 degrees - 125 degrees ). The average femorotibial angle (FTA) was corrected from the pre-operative. 27.6 degrees (20 degrees - 40 degrees ) to the post-operative 6.8 degrees (5 degrees - 9 degrees ). The Knee Score System (KSS) score and functional score were improved from the pre-operative 22.7 points (9 - 48 points) and 26.5 points (12 - 55 points) to the post-operative 86.4 points (85 - 95 points) and 89.1 points (80 - 95 points) respectively. Follow-up showed that the FTA remained unchanged and the knee stability of all patients was good. CONCLUSION: Through lateral approach, "Z" plasty of the capsule can release the lateral structure and decrease the pressure of common peroneal nerve. For TKR with moderate to severe fixed valgus knee, lateral approach is an effective way to correct the deformity.

[Total knee replacement in valgus knee].

OBJECTIVE: To investigate the methods and clinical results of total knee replacement (TKA) in patients with valgus knee deformity. METHODS: Between January 1996 and August 2004, 87 TKAs were performed by means of medial parapatellar approach, standard osteotomy and only lateral soft tissue release with posterior stabilized implants on 74 patients (11 men and 63 women) with valgus deformity. The average age at the time of operation was 62.93 years (range, 26-80 years). Clinical and radiographic evaluations including range of motion (ROM), Knee Society Score System (KSS) and the tibial and femur angle (T-F angle) were performed at follow-up. RESULTS: After a mean follow-up of 33.8 months (range, 5 months-9 years), the average ROM improved from 91 degrees (range, 70 degrees-120 degrees) preoperatively to 112.4 degrees (range, 80 degrees-130 degrees) postoperatively, the average KSS improved from 22.7 points (0-48 points) preoperatively to 81.7 points (range, 71-93 points) postoperatively. The average function score improved from 26.5 points preoperatively to 86.3 points postoperatively, the average T-F angle was corrected from 21.59 degrees (range, 12 degrees-40 degrees) of valgus preoperatively to 8.7 degrees (0 degrees-11 degrees) of valgus postoperatively. One knee had lightly instability at follow-up, one knee with patellar dislocation preoperatively had subdislocation postoperatively, no other complication occurred. CONCLUSIONS: The techniques of medial parapatellar approach, standard osteotomy and only lateral soft tissue release with posterior stabilized implants can correct a fixed valgus deformity very successfully in patients undergoing primary total knee replacement, and provides excellent results.

[A comparison study of interbody cage in lumbar degenerative disease].

OBJECTIVE: To compare the advantages and disadvantages of TFC/BAK, Prospace and Brantigan I/F carbon cages and summarize their applications. METHODS: One hundred and twelve cases of Brantigan I/F, 123 cases of TFC/BAK and 45 cases of Prospaces were used in the treatment of degenerated lumbar disorders. The clinical results and complications were observed and analyzed. RESULTS: All devices restored the height of intervertebral space and achieved immediate stability after insertion. One hundred and twelve cases of Brantigan I/F cages were solid fused, the clinical results were satisfactory. Three cases of TFC/BAK cages subsided into the vertebra and 2 cages retropulsed slightly during follow-up. There was no serious complications of nervous system, but the operation time and amount of bleeding in Brantigan I/F group increased. CONCLUSIONS: Carbon fiber intervertebral cages are an effective method in treating degenerated lumbar disorders. To avoid complications, the indications and techniques must be selected carefully.

[Surgical treatment of degenerative scoliosis].

OBJECTIVE: To investigate the techniques and indications of treatment of degenerative scoliosis. METHODS: The clinical data of 45 degenerative scoliosis patients, 18 males and 27 females, aged 41 - 77, all suffering from severe low back pain, were analyzed. Twenty of them underwent posterior lumbar interbody fusion with pedicle screws combined with correction of scoliosis. Sixteen patients underwent depression of vertebral canal and pure internal fixation and fusion of pedicle. Eight patients underwent pure depression, such as laminectomy or incision of intervertebral foramen. The corrective effects of scoliosis, condition of intervertebral fusion, and complications were observed. RESULTS: All operations were performed successfully and all the patients made a remarkable recovery. During the 13 months' follow-up, 88% of the patients showed remarkable relief from pain and claudication and improved life quality. No loss in correction angle and height of disc space was found among the patients who had undergone internal fixation and interbody fusion. The residual symptom of low back pain was more manifest in the patients who had not undergone internal fixation than in those who had. CONCLUSION: Posterior lumbar interbody fusion with pedicle screws is safe and effective in the treatment of severe degenerative scoliosis.

[Application of intervertebral carbon fiber cage in degenerated lumbar disorders].

OBJECTIVES: To evaluate the effect of intervertebral carbon fiber cages in the treatment of degenerated lumbar disorders. METHODS: One hundred and twelve patients of degenerated lumbar disease were analyzed retrospectively with regard to the effect of posterior lumbar interbody fusion (PLIF) using intervertebral carbon fiber cage. RESULTS: In the 112 patients, disc height was 7 mm (3 to 11 mm) on average before operation and 11.2 mm (8 - 14 mm) after operation. Cobb angle was 32 degrees (21 degrees to 42 degrees ) on average before operation and 18.9 degrees (13 degrees to 21 degrees ) after operation. After follow-up for 7.8 months (4 to 13 months) on average, all operative disc spaces showed solid arthrodesis through X-ray images. Disc height was 10.9 mm (8 - 14 mm) on average, and Cobb angle was 18.5 degrees (13 degrees to 21 degrees ) on average. During the follow-up, endplate absorbing, pseudo-articulation, cage displacement, subsidence, and breaking were not found. CONCLUSION: Implantation of intervertebral carbon fiber cages is an effective method for the treatment of lumbar degenerative disease. Accurate indications and skilled techniques are required to avoid complication.

[Surgical treatment of degenerative scoliosis].

OBJECTIVES: To investigate the techniques of posterior lumbar interbody fusion and pedicle screws in the treatment of degenerative scoliosis and evaluate their clinical significance. METHODS: Twenty five patients with degenerative scoliosis were treated operatively during 1997 - 2002. Among the 25 patients, 13 patients were treated with Brantigan I/F carbon cages in 28 intervertebral spaces, 7 patients were treated with Prospace cages in 15 spaces, 1 patient was treated with CONTACT cages in 2 spaces. The correcting effects, complications and follow-up results were analyzed retrospectively. RESULTS: The average correction rate of scoliosis was 59% and the rate of pain relief was 88%. There was a case of pseudoarthritis and a case of embolism. During follow-up, correction rate and height of disc spaces were not lost nor shift of interbody cages. CONCLUSION: Posterior pedicle screws combined with interbody fusion is a safe and effective treatment for degenerative scoliosis.