The Survivorship and Clinical Results of Minimally Invasive Unicompartmental Knee Arthroplasty at 10-Year Follow-up

BACKGROUND: In this study, we investigated the long-term clinical results and survival rate of minimally invasive unicompartmental knee arthroplasty (UKA) by collecting cases that had been implanted more than 10 years ago. METHODS: One hundred and twenty-eight patients (166 cases) who underwent Oxford phase 3 medial UKA using the minimally invasive surgery from January 2002 to December 2002 were selected. The mean age of the patients at the time of surgery was 61 years, and the duration of the follow-up was minimum 10 years. Clinical and radiographic assessments were performed using the Knee Society clinical rating system, and the survival analysis was done by the Kaplan-Meier method with 95% confidence interval (CI). RESULTS: The mean Knee Society knee and function scores improved significantly from 53.8 points (range, 25 to 70 points) and 56.1 points (range, 35 to 80 points) preoperatively to 85.4 points (range, 58 to 100 points) and 80.5 points (range, 50 to 100 points) at 10-year follow-up, respectively (p < 0.001). Failures following the UKA occurred in 16 cases (9.6%), and the mean time of the occurrence of the failure was 6.2 years after the surgery. The 10-year survival rate was 90.5% (95% CI, 85.9 to 95.0) when failure was defined as all the reoperations, whereas the 10-year survival rate was 93.4% (95% CI, 89.6 to 97.1) when the cases in which only revision total knee arthroplasty was defined as failure. CONCLUSIONS: The results of this study show outstanding functions of the knee joint and satisfactory 10-year survival rate after minimally invasive UKA. Therefore, minimally invasive UKA could be a useful method in the treatment of osteoarthritis in one compartment of knee joint.

Management of Patients with L2 Spinal Nerve Root Block Who Are Suffering from Low Back and Referred Pain

STUDY DESIGN: Prospective clinical study. OBJECTIVES: The aim of the study was to verify the effectiveness of L2 spinal nerve root block for patients who are suffering from low back pain and referred pain with compound causes. SUMMARY OF LITERATURE REVIEW: Most of low back pain and referred pain arises from discs, facet joints and sacroiliac joints. All structures above have the pain perception pathway through sympathetic nerves with a connection to L2 spinal nerves. MATERIALS AND METHODS: We selected patients with low back pain and referred pain for more than 2 weeks. Each 50 patients were randomly allocated to an experimental and a control group.The experimental group underwent a L2 spinal nerve root block with 2cc of 0.25% bupibacaine at the symptom dominant side. The control group underwent a skin infiltration with 2cc of 2% lidocaine only. The pain was assessed with a visual analogue scale (VAS) consisting of 100 points at 5minutes, day 1, day 3, day 5, day 7 and day 30 postprocedure. RESULTS: Both groups showed a significant improvement after the procedures(p=0.000). However, a greater improvement was shown in the experimental group(p=0.000). In the individual analysis, the experimental group had improved as time elapsed and the significancewas maintained until 30 days. However, in control group, the significance was lost at day 30. CONCLUSION: L2 spinal nerve root block is recognized to reduce the low back and referred pains which arise from compound causes in a degenerative spinal disease.

Demineralized Bone Matrix, as a Graft Enhancer of Auto-Local Bone in Posterior Lumbar Interbody Fusion

STUDY DESIGN: A case controlled study with prospective data collection. PURPOSE: To evaluate the early influence and the final consequence of demineralized bone matrix (DBM) on auto-local bone as a graft enhancer in posterior lumbar interbody fusion (PLIF). OVERVIEW OF LITERATURE: DBM is known as an osteoinductive material; however, it has not been clearly recognized to enhance auto-local bone with a small amount. METHODS: Patients who had a PLIF were allocated into two groups. Group I (70 cases) used auto-local bone chips and group II (44 cases) used DBM as an additive to auto-local bone, 1 mL per a segment. Group selection was alternated. Early assessment was performed by computed tomography at 6 months and final assessment was done by simple radiography after 24 months at least. The degree of bone formation was assessed by 4 grade scale. RESULTS: The subjects of both groups were homogenous and had similar Oswestry Disability Index at final assessment. The ratio of auto-local bone chips and DBM was 6:1. The degree of bone formation at 6 months after surgery was superior in group II. However, there was no significant difference between the two groups at the final assessment. CONCLUSIONS: DBM was not recognized to enhance auto-local bone with small amount.

Total Knee Arthroplasty after Failed Unicompartmental Knee Arthroplasty / 대한정형외과학회잡지

PURPOSE: To identify the causes of failure after unicompartmental knee arthroplasty (UKA), and to evaluate considerations for surgical procedures and the results of revision total knee arthroplasty (TKA) performed after failure of UKA. MATERIALS AND METHODS: Eight hundreds and fifty-two cases of UKA were performed from January 2002 to June 2011. Forty-seven cases of failures after UKA were analyzed for the cause of the failures, and thirty-five cases of revision TKA after failure were analyzed for the operative findings and surgical technique. The clinical results were measured for thirty cases which were followed-up on at least two years after TKA. The mean duration of follow-up was four years and one month after revision TKA and the mean patient age at the time of surgery was sixty-five years. RESULTS: For the cause of failures after UKA, there were twenty-two cases of early loosening of prosthesis, seventeen cases of simple mobile bearing dislocation, five cases of infection, one case of fracture of medial tibial condyle and two cases of unknown origin pain. In operative findings of thirty-five cases of TKA after failed UKA, there were twenty-seven cases of bone defect requiring treatment and the mean thickness of the defect was 10.6 mm. For the treatment of bone defect, there were five cases of autogenous bone graft, twenty-one cases of metal blocks, and one case of autogenous bone graft with metal block. The stem was used in tibial implants for nineteen cases, and one case of use in tibial and femoral implants. For thirty cases where follow-ups were possible at least two years after operation, the mean knee score was improved from 68.2 to 85.2 and the mean knee function score was improved from 67.7 to 78.0 at the last follow-up, respectively. The mean range of knee motion was 107.2degrees pre-operatively, which was recovered to 120.7degrees after the operation. The mean tibiofemoral angle was changed from 1.7degrees of valgus to 5.2degrees of valgus. CONCLUSION: As shown in this study, the tibial bone defect was the most important problem in revision TKA after failure of UKA. Therefore, proper indication and accurate surgical technique using autogenous bone graft, metal block and stemmed implants would be able to achieve satisfactory results in revision TKA after failure of UKA.

The Tourniquet Pressure 200 mmHg for Total Knee Arthroplasty: is it possible? / 대한정형외과연구학회지

PURPOSE: To evaluate the possibility of lowering tourniquet pressure to 200 mmHg during total knee arthroplasty (TKA) by pressing the femoral artery. Lowering the toniquette pressure can attribute to minimize the soft tissue damage and pain after the operation. MATERIALS AND METHODS: We analyzed patients who had TKA from Sep 16th, 2010 to Mar 3rd, 2011. Among them, 35 patients (test I) had operations on both knees, and 50 patients (test II) underwent operation on one knee. We excluded the patients who had a previous operation, infection, or bleeding tendency. We put a cotton roll at the antero-medial side of the thigh just under the tourniquet in order to apply more pressure on the femoral artery that is scanned by ultrasonography. We scored 0 on non-bleeding, 1 on bleeding that did not affect the operation, and 2 on bleeding which disturbed the operation. RESULTS: In test I, the group which applied 200 mmHg with local pressure, 24 patients (68.6%) scored 0, 9 patients (25.7%) scored 1, and two patients (5.7%) scored 2. In the other group used pressure 250 mmHg, however, 31 patients (88.6%) scored 0, 4 patients (11.4%) scored 1, and no one scored 2 (p=0.039). Totally, in the 200 mmHg group with local pressure, 33 patients had no problem in surgery, and only for 2 patients (5.7%), we had to increase pressure. For the patients with 250 mmHg, however, we had to increase pressure on nobody (0%). In test II, in the group which had operation on one knee with 200 mmHg with local pressure, 14 patients scored 0, 8 patients scored 1, and one patient scored 2. Also in the 250 mmHg group, 24 patients scored 0, 2 patients scored 1, and one patient scored 2. (p=1.000). Overall results demonstrate no differences in bleeding that disturb operations statistically. CONCLUSION: Even with a little more bleeding compared to the 250 mmHg group, 94.8% of patients can have operation with no bleeding problems by using a cotton roll and the pressure 200 mmHg. For successful operations, there is no difference between groups using 250 mmHg and 200 mmHg with local pressure on femoral artery.

Causes of Femoral Component Radiologic Abnormality After Total Knee Arthroplasty Using Legacy Posterior Stabilized-Flex Prosthesis / 대한정형외과연구학회지

PURPOSE: We analyzed the causative factors of femoral component radiologic abnormality after total knee arthroplasty (TKA) using a Legacy Posterior Stabilized (LPS)-Flex prosthesis. MATERIALS AND METHODS: 140 cases of TKA using LPS-Flex and 140 cases of Vanguard from Jan 2008 to June 2010 were analyzed and radiographic abnormalities around the femoral stems were compared. Secondly, TKA using LPS-Flex was divided into two groups according to the posterior femoral cutting technique, which were single cutting method and additional cutting method. Accuracy of the femoral posterior resection was compared. RESULTS: Radiographically, anterior radiolucent line was found in eight cases with LPS-Flex but no case with Vanguard. Posterior overhang more than 30% was found in ten cases in both groups. Posterior bone defect more than 50% was found in 23 and seven cases respectively. Anterior radiolucent line and posterior bone defect were observed significantly more in LPS-Flex. In the second study, we found femoral posterior bone defect in 20 cases with additional cutting method which was caused by flexion of the femoral box-cutting guide. CONCLUSION: Posterior bone defect from LPS-Flex was caused by inappropriate resection due to flexion of the box cutting guide. Single cutting method should be adopted for more accurate posterior femoral cutting.