Faculty Bibliography

Operative correction for infantile and adolescent tibia vara has been described using both external and internal fixation. Gradual correction using a circular fixator offers the advantage of accurate coronal, sagittal, and axial plane correction without significant soft tissue dissection. This study evaluated the use of six-axis deformity analysis and the Taylor Spatial Frame (TSF) for the correction of tibia vara. Nineteen patients (22 tibias), 6 with infantile and 13 with adolescent tibia vara, underwent correction with TSF. On the basis of mechanical axis correction, 21 of 22 tibias were corrected within 3 degrees of normal. Using Schoenecker's criteria, all patients achieved good results (no pain, <5 degrees difference in tibial-femoral angle from the normal side). Complications included one intractable pin-site infection, two superficial pin-site infections, and one delayed union. Six-axis deformity analysis and TSF provide accurate and safe correction of infantile and adolescent tibia vara

The Ponseti casting technique is reported to have a high success rate in the treatment of idiopathic clubfoot. Non-operative treatment of clubfoot provides a lower complication rate, less pain, and higher function as the patient ages than operative treatment. To demonstrate serial post-treatment change in clubfeet over time, three clubfoot rating systems were utilized in the current study. Patients compliant with the Ponseti technique and treated before the age of 7 months, had a 92% success rate at an early follow-up after casting was completed. It is not the purpose of this article to analyze the long-term clubfoot treatment result but to establish tools which can be used to judge initial success with the Ponseti technique. Complications are few and minor, limited to equipment used and cast technique

Twenty patients with Type II clubfeet were evaluated an average of 3.1 years after complete surgical soft tissue release. A pinned group had fixation of the talonavicular and calcaneocuboid joints and a non-pinned group had no fixation. The control group consisted of 10 children without foot ailments. Radiographic measurements of talocalcaneal and talus-first metatarsal angles and frequencies of dorsal and medial navicular subluxation were not different for the two treatment groups. Foot progression angle was not significantly different for the two treatment groups, but was significantly different between all clubfoot patients (3.6 degrees of in-toeing) and the control group (5.0 degrees of out-toeing). Tourniquet time was significantly greater for the pinned than for the non-pinned group, but the duration of surgery was similar. Similar radiographic and gait measurement findings suggest that clubfoot surgery with and without percutaneous fixation have comparable outcomes

Although the etiology of congenital clubfoot remains unknown, reproducible pretreatment grading now seems possible. However, the lack of an agreed-on and reproducible posttreatment evaluation system still hinders outcome studies of the treatment of clubfoot. The literature from about 1970 to 1990 contains enthusiastic reports on the correction of congenital clubfoot through extensive surgical release procedures. Over time, we have come to recognize the complications of such surgery, including recurrence, overcorrection, stiffness, and pain (WJ Shaughnessy, MD, P Dechet, MD, HB Kitaoka, MD, Vancouver, BC, Canada, unpublished data, 2000). Perhaps because of these findings, there is a renewed interest in nonsurgical techniques for the correction of congenital clubfoot. Recent studies have documented the effectiveness of the two leading techniques involving serial manipulation and cast treatment. The Ponseti technique appears to be effective and requires only a reasonable amount of time out of the lives of the patient and his or her parents. The technique frequently includes some minimally invasive surgery. The Kite and Lovell technique requires minimally invasive surgery less often but is more time consuming. French investigators and others have introduced new ideas that may reduce the need to immobilize the foot. The French approach requires fairly extensive physical therapy and demands substantial parental time and attention. It is not yet clear that the French technique is more successful in obviating the need for surgery than is expertly applied serial manipulation and cast immobilization. It also has not been proved that the long-term results of the French technique are better than those of serial manipulation and cast immobilization. It is probably that unless the French technique is found to substantially decrease the need for surgery, it will prove to be less cost effective than serial manipulation and cast immobilization. It is likely that a small number of clubfeet will require surgery even after expertly applied nonsurgical treatment. However, it is hoped that such surgery will be less extensive than procedures commonly performed in the recent past

Between 1994 and 1998, seven adolescents underwent hip arthrodesis with the use of an external fixator. Mean time of follow-up was 24.0 months after surgery. The duration of fixation and time to fusion were 6.6 months (range, 5-9.5 months) and 8.0 months (range, 5.2-15 months), respectively. At most recent follow-up, there was a significant improvement in the mean modified Harris hip score, in which the maximum score is 91 points after omitting 9 points for hip range of motion and deformity, from 25.7 before surgery to 66.7 after surgery (p < 0.01). The advantages of this procedure include (i) the ease and accuracy of obtaining the proper position for fusion, (ii) the ability to lengthen the affected leg at the same time, (iii) the diminished likelihood of compromising future hip operations, and (iv) the ability to ambulate and bear weight throughout the treatment course. We recommend this method of hip arthrodesis with external fixation for patients with intractable hip pain necessitating this procedure

Congenital pseudoarthrosis of the tibia remains one of the most difficult conditions to treat in orthopedic surgery. Seven cases were treated in our hospital by different methods. Three out of seven patients were healed, two of these refractured. At follow-up, the success rate was 14% (one out of seven cases). It is our recommendation that early primary amputation with an appropriate prosthesis should be considered, and that the final evaluation should not be based on obtaining bone union, but on the level of function of the lower extremity

Past attempts to detect tropomyosin in electron micrograph images of frozen-hydrated troponin-regulated thin filaments under relaxing conditions have not been successful. This raised the possibility that tropomyosin may be disordered on filaments in the off-state, a possibility at odds with the steric blocking model of muscle regulation. By using cryoelectron microscopy and helical image reconstruction we have now resolved the location of tropomyosin in both relaxing and activating conditions. In the off-state, tropomyosin adopts a position on the outer domain of actin with a binding site virtually identical to that determined previously by negative staining, although at a radius of 3.8 nm, slightly higher than found in stained filaments. Molecular fitting to the atomic model of F-actin shows that tropomyosin is localized over sites on actin subdomain 1 required for myosin binding. Restricting access to these sites would inhibit the myosin-cross-bridge cycle, and hence contraction. Under high Ca(2+) activating conditions, tropomyosin moved azimuthally, away from its blocking position to the same site on the inner domain of actin previously determined by negative staining, also at 3.8 nm radius. These results provide strong support for operation of the steric mechanism of muscle regulation under near-native solution conditions and also validate the use of negative staining in investigations of muscle thin filament structure.

A subset of postoperative recurrent clubfeet was isolated in a group of patients 4 to 8 years old. Twenty-seven consecutive patients who underwent redo surgery consisting of complete soft tissue clubfoot release combined with a calcaneocuboid fusion were reviewed for this study. Twenty-six feet of 27 feet in 20 patients had a long-term good result, suggesting that this procedure is the one of choice for this age group