Can the Surgical Approach to Total Knee Arthroplasty Influence Early Postoperative Outcomes? - A Comparative Study between Trivector and Medial Parapatellar Approaches.

BACKGROUND: Trivector approach to total knee arthroplasty (TKA) is a quadriceps tendon sparing approach, whereas the medial parapatellar (MPP) approach involves making a longitudinal incision in quadriceps tendon. We postulated that quadriceps-sparing approach such as trivector should make postoperative rehabilitation easier and ultimately reduce the length of hospital stay. OBJECTIVES: The aim of the study is to compare the early postoperative outcomes of the TKA performed through the trivector and the MPP approaches. METHODOLOGY: We prospectively reviewed the results of 56 consecutive patients operated on by two knee surgeons: one routinely performs trivector and the other an MPP approach. Both the groups consisted of 28 patients each. We looked at operative times, the time taken to perform straight leg raise (SLR), range of movements achieved before discharge, and length of the hospital stay. RESULTS: The mean time taken for performing the surgery through the MPP approach was 56 min, whereas, for the trivector approach, it was 54 min (P = 0.31). The mean time taken to perform SLR in the MPP approach group was 3.5 days, whereas in the trivector group, the meantime taken for SLR was 2.5 days (P = 0.003). The average extension at the time of discharge in the MPP group was 3.8°, and in the trivector group, it was 0.86° (P = 0.007). The average knee flexion at the time of discharge in the MPP group was 84.2°, whereas in the trivector group, it was 86.5° (P = 0.199). The average hospital stay in the MPP group was 5.96 days, whereas in the trivector group, it was 4.84 days (P = 0.11). CONCLUSIONS: The trivector approach patients took significantly less time to do SLR and achieved a better range of extension before discharge from the hospital. The patients with trivector approach were discharged early by one day, although it is not statistically significant, it is clinically significant.

Dural tears in primary decompressive lumbar surgery. Is primary repair necessary for a good outcome?

STUDY DESIGN: Case control series with prospective data collection. OBJECTIVE: To establish whether incidental durotomy treated without primary suture repair adversely affects the outcome following lumbar surgery in the longer term. METHOD: Outcome scores from a prospective database were used for an audit of dural tears in primary lumbar decompressive surgery. Outcome data collected includes the Short Form 36 General Health Questionnaire (SF36), the Oswestry Disability Index (ODI) and Visual Analogue Scores for leg pain (VAL) and back pain (VAB). RESULTS: Out of 200 consecutive procedures, a dural tear occurred in 19 (9.5%) patients. Of 19 patients with a dural tear, data was incomplete in 4 patients, and 1 further patient who had their dural tear sutured was excluded, leaving 14 patients to be studied. There were seven males and seven females, with an average age of 50.8 years (31-69). These 14 patients (group 1) were compared to a matched group (age, sex, surgical diagnosis and duration of follow-up) of 14 patients (group 2) with no tear. Both groups had similar pre-operative scores. At 6-month follow-up, both groups had significant improvements in all outcomes measures except for the general health domain of the SF-36. At final follow-up, patients with dural tears appeared to have better improvements in outcome measures amongst the VAB, VAL and ODI with similar scores in the SF-36 domains. CONCLUSION: Our study demonstrates that incidental durotomy in primary lumbar decompressive surgery can be successfully managed without primary suture repair with no adverse effect on surgical outcome in the longer term.

Total knee arthroplasty in patients with excessive external tibial torsion >45° and patella instability--surgical technique and follow up.

Patients presenting with advanced knee osteoarthritis (OA), excessive external tibial torsion (EETT) and chronic patella subluxation pose significant surgical challenges. A combination of TKA, tibial derotation osteotomy, and tibial tuberosity transfer was performed in ten patients (twelve knees) with OA secondary to EETT and patellar instability. Six weeks of non weight-bearing and flexion limited to 45° was mandated after surgery. The mean follow-up and patient age was 81months (range, 14 to 159) and 56years (range, 49 to 62). The mean pre-operative external tibial torsion was 62°, with an average rotational correction of 30°. Significant improvement was found in the Knee Society Score, SF-12 and all WOMAC questionnaire score subscales (p<0.0001); 5 patients had complications, but no loosening or nonunion was seen.

Comparison of cement pressurisation in flanged and unflanged acetabular cups.

BACKGROUND: This biomechanical study examined difference in cement pressures generated by flanged and unflanged acetabular cups in hip arthroplasty. METHOD: Using a model acetabulum, cement was inserted and pressurised followed by cup insertion and pressurisation. Pressures were recorded using transducers in the acetabulum. We compared Charnley Ogee (flanged), Exeter contemporary (flanged) and Exeter low profile (unflanged) cups using Simplex and CMW1 cements in turn. RESULTS: Using Simplex, Charnley Ogee cup generated highest initial peak pressure and overall mean pressure. Exeter unflanged cup generated higher initial and mean pressures compared to Exeter flanged cup. With CMW, there was no significant difference between the pressures generated by the cups. CONCLUSIONS: Our experiment suggests that flanged cups do not consistently generate significantly higher cement pressures compared to unflanged cups.

The risk of avascular necrosis following chevron osteotomy: a prospective study using bone scintigraphy.

Controversy exists with regard to the effects of chevron osteotomy on blood supply and subsequent development of avascular necrosis (AVN) of the first metatarsal head. The aim of this study was to assess the incidence of avascular necrosis in our centre following chevron osteotomy for hallux valgus, using bone scintigraphy. Thirty nine patients who had a chevron osteotomy for treatment of hallux valgus were prospectively studied. Mean follow-up was 14 months. Bone scintigraphy was used to assess metatarsal head perfusion at an average 8.5 weeks post operatively. Three patients (7.7%) showed abnormal bone scan around the metatarsal head. Further evaluation of these patients did not show any sign of AVN. We conclude there appears to be a risk of circulatory disturbance to the metatarsal head following chevron osteotomy of the first metarsal (7.7% in this study); however this does not translate into clinically significant AVN.

Survivorship analysis at 15 years of cemented press-fit condylar total knee arthroplasty.

We performed a survival analysis on 354 cemented primary press-fit condylar total knee arthroplasties in 277 patients with prospective follow-up (mean, 8.8 years; range, 0.3-16.9 years). The number of patients alive reaching 15 years at follow-up for survival analysis was 15. The cumulative survival rate at 15 years was 81.7% (95% confidence interval, 72.1%-88.5%), using revision for all causes as our end point. Indications for revision in our patient group were aseptic loosening 4.5%, infection 2.3%, and exchange of polyethylene insert 1.1%. Our results indicate that the cemented press-fit condylar total knee arthroplasty has a good long-term survival, at 15 years, based on revision as the end point.

Perioperative changes in the microcirculation in feet after foot and ankle surgery.

The senior author (N.P.G.) observed that if the foot became dependent in the first 48 hours after foot surgery, the patient had swelling and pain. This effect seemed less after about 48 hours. The authors set out to see if there was a scientific basis for this. Laser Doppler was used to assess blood flow in 14 patients. Flow was recorded in the big toe, at heart level, and on dependency, preoperatively and postoperatively. Postural vasoconstriction was calculated, and time for blood flow to normalize was recorded. Mean postural vasoconstriction preoperatively was 51.31%; postoperative mean at 24 hours was 23.05%, at 48 hours 36.62%, and at 72 hours 44.24%. There was a difference between the preoperative levels and the 24-, 48-, and 72-hour postoperative levels (P < .05). Results showed that it takes longer than 72 hours rather than 48 hours for microcirculation to return to normal. The results emphasized the importance of postoperative foot elevation for at least 48 hours because of this phenomenon.