Michael P. Kennedy

The validity and reliability of the Klaue device.

Background: Excessive first ray mobility has been implicated as the cause of many forefoot abnormalities. The association between hypermobility and forefoot pathology is controversial, and this is largely related to the difficulty in quantifying first ray motion. Manual examinations have been shown to be unreliable. Klaue et al. developed a device consisting of a modified ankle-foot orthosis with an attached micrometer to objectively measure first ray mobility. The purpose of this study was to evaluate the validity and reliability of this device. Methods: Sixteen fresh-frozen, below-knee amputation specimens with hallux valgus were used for the study. The study was divided into two parts. Part I was an analysis of the validity of the Klaue device; first ray dorsal displacement was measured on lateral radiographs following manual manipulation, and values were statistically compared to the Klaue device measurements. Part II of the study was an evaluation of intraobserver and interobserver agreement. Two clinicians used the Klaue device on each of the cadaver limbs, and values of first ray sagittal mobility were recorded and compared. Results: The mean value of first ray mobility measured with the Klaue device was 7.5 mm and the average displacement measured from the lateral radiographs was 7.4 mm. Paired t-testing showed no significant difference between the Klaue and radiographic measurements (p = 0.83). The mean first ray mobility by examiners 1 and 2 with the Klaue device were identical (10.5 mm), and statistical analysis showed no significant interobserver or intraobserver differences. Conclusions: The results confirm the validity of the Klaue device and limited variability of measurements between experienced users.

Coralline hydroxyapatite bone graft substitute in hindfoot surgery

Background: Coralline hydroxyapatite bone graft substitute material is created by the conversion of the calcium carbonate structure of coral into hydroxyapatite. The microstructure of the material resembles cancellous bone and provides an osteoconductive scaffold for bone ingrowth. The use of this material is reported in the orthopedic oncology and trauma literature. Short-term reports in foot procedures have been reported. Method: A retrospective review identified 10 patients who had undergone hindfoot arthrodesis with coralline hydroxyapatite bone graft. The charts were reviewed for outcomes, operative complications, and time to union. Nine of the 10 patients were available for additional examination. Results: The average followup was 6 years. There were three complications. One patient had sural nerve numbness with partial resolution which was unrelated to the graft material. A rheumatoid patient on methotrexate and prednisone developed a deep wound infection 9 months after surgery. One patient had a nonunion of the talonavicular joint. Eight of the 10 patients reported good or excellent results. Radiographs continued to demonstrate the presence of the graft material at 6 years. Radiographs showed extrusion of the graft from the joint in all patients. No patient had symptoms from the extruded material. Discussion: Coralline hydroxyapatite bone graft substitute appears to be a clinically effective material for use in foot procedures. No adverse events could be linked to the graft material. The graft material is difficult to contain and extrusion was present in all patients. The slow resorption is a concerning characteristic of the graft material. At 6-year followup, the continued presence of the material has not shown any adverse effect.

First Metatarsophalangeal Joint Motion After Hallux Valgus Correction: A Cadaver Study

Background: Surgical correction of hallux valgus deformities often results in decreased first metatarsophalangeal joint (MTPJ) range of motion. Loss of motion has been shown to affect patient satisfaction. The purpose of this study was to evaluate the immediate change in MTPJ range of motion that occurs after a distal soft-tissue reconstruction (DSTR) and proximal metatarsal osteotomy (PMO). Methods: DSTR and PMO were done on 16 below-knee cadaver specimens with clinically apparent hallux valgus deformities. Two examiners assessed preoperative and postoperative dorsiflexion (DF), plantarflexion (PF), and the total range of motion of the first MTPJ. The hallux valgus angle (HVA) and 1–2 intermetatarsal angle (1–2 IMA) were measured on simulated weightbearing radiographs before and after operative correction. Changes in motion were analyzed and correlated with the angular measurements. Results: The mean total range of motion preoperatively was 85.4 degrees (DF 70.5 degrees, PF 14.9 degrees) and significantly decreased (p < 0.005) 23.2 degrees to a postoperative value of 62.2 degrees (DF 47.9 degrees, PF 14.3 degrees). There was a significant (p < 0.005) decrease in DF (22.6 degrees) with the operative correction, but the loss of PF (0.6 degrees) was not significant (p = 0.7). There was no correlation between the magnitude of correction (HVA, 1–2 IMA) and the change in PF, DF, or total motion. Conclusions: Correction of a hallux valgus deformity with a DSTR and PMO is associated with an immediate loss of range of motion that primarily affects the DF arc of the first MTPJ. The selective loss of DF may be related to a nonisometric capsular repair or tight intrinsic musculature, although there was no correlation with the magnitude of angular correction. The immediate decrease in motion observed in this cadaver study underscores the importance of early postoperative joint mobilization to prevent long-term stiffness after bunion surgery.

Operative repair of fourth and fifth toe corns.

Methods: We report a retrospective review of 57 consecutive patients (72 feet) over a period of 20 years who had been treated operatively for either a lateral fifth toe corn or an interdigital corn of the fourth interdigital space more than two years previously. Of these, 51 patients (62 feet) returned for a follow-up evaluation at a minimum of two years (average of over seven years) which included a review of the interval history since the surgery, a physical examination, a radiographic evaluation, and assessment of the patients satisfaction with the alignment and results of surgery. Treatment of 31 lateral fifth toe corns involved either a lateral condylectomy and flexor tenotomy or a complete condylectomy. Treatment of 31 interdigital corns comprised either a single condylectomy, double condylectomy of adjacent corns, or a complete condylectomy (hammertoe repair) of a symptomatic corn. Treatment in each case was dependent upon the severity of the deformity. Results: There was found to be no significant difference in comparison of the two major groups (interdigital corns and lateral fifth toe corns) with the measurement of the relative length of the fourth and fifth metatarsals, toe malalignment, angulation of the fourth and fifth toes (MTP-4, MTP-5 angles), and the phalangeal-5 angle. Pain was relieved in 58 of 62 feet (93%) and subjective acceptable alignment was achieved in 54 of 62 feet (87%). At final follow-up 53 feet were rated by patients as excellent, seven as good, one as fair, and one as poor. Complications included numbness of the involved digit (six feet). There were two superficial infections. There were two cases of joint instability due to excessive bone resection. Joint stiffness was commonly observed (34/62 feet, 55%), but was not associated with diminished satisfaction at final follow-up. Mild asymptomatic recurrence of a callosity was noted in 10 feet and moderate or severe recurrence was noted in two feet. Dissatisfaction was associated with moderate or severe recurrence. Conclusion: In this retrospective study at an average of more than seven years, we achieved a high level of patient satisfaction treating both lateral fifth toe corns and interdigital corns with a partial and/or complete condylectomy, the choice depending upon the magnitude of the deformity and the callus, and the fixed nature of the lesser toe deformity.

First metatarsocuneiform joint mobility: Radiographic, anatomic, and clinical characteristics of the articular surface

Background: The first metatarsocuneiform joint is involved in first ray biomechanics and related forefoot pathology. The purpose of this study was to evaluate the first metatarsocuneiform joint radiographic findings in relation to angular position of the radiographic beam, and to assess the joint mobility as it relates to the anatomic orientation of the facets on both radiographic imaging and gross anatomic dissection. Methods: Thirty-nine cadaveric lower extremity limbs were stratified as normal, mild, moderate, or severe hallux valgus deformity. Mobility of the first metatarsocuneiform joint for each specimen was assessed using the Klaue device. The medial inclination angle (obliquity) of the first metatarsocuneiform joint was determined on both 10-degree and 20-degree anteroposterior radiographs. The lateral inclination angle of both the dorsal and plantar facets was determined on lateral radiographs. Each specimen was then dissected to directly inspect the metatarsocuneiform joint. Results: The metatarsocuneiform joint mean height was 28.3 mm and the mean width was 13.1 mm. Twenty-three feet demonstrated a continuous cartilaginous surface, 15 feet demonstrated a bilobed cartilaginous surface, and 1 foot demonstrated completely separated facets. Dorsal facets were curved in 37 specimens and flat 2 specimens. Plantar facets were flat in 30 specimens and curved in 9 specimens. The medial inclination angle measured 15.8 degrees on the 10-degree radiograph and 2.6 degrees on the 20-degree radiograph. We were unable to establish any correlations of metatarsocuneiform joint angles or facet contour with mobility measured by the Klaue device. Conclusions: The metatarsocuneiform joint has a height to width ratio of nearly 2:1. Continuous and bilobed facets are both very common anatomic variants. The contour of the dorsal facet was predominantly curved and the contour of the plantar facet was predominantly flat. First metatarsocuneiform joint mobility does not appear to be dependent on the contour of the facets or the degree of medial inclination of the joint. Clinical Relevance: Anatomic and radiographic findings with regard to mobility of the first metatarsocuneiform joint may assist the surgeon in interpreting the joint’s relationship to hallux valgus deformity and to aid in clinical decision making. Our findings suggest that radiographic interpretation of medial inclination is unreliable and should not be used to determine the appropriateness of specific operative procedures.

Articular chondral damage of the first metatarsal head and sesamoids: Analysis of cadaver hallux valgus

Background: Evidence of successful correction on postoperative hallux valgus imaging studies may not always correlate with patient satisfaction. Recent attention to the association of cartilaginous degeneration and hallux valgus may provide new insight into treatment algorithms and patient expectations. The purpose of this cadaveric study was to evaluate the degree of chondral damage as it relates to increasing hallux valgus deformity. Methods: A total of 39 cadaver first metatarsophalangeal joints were evaluated by radiography, and then dissected to evaluate for chondral damage. Chondral lesion grade, size, and location were recorded and then analyzed based on patient demographics and hallux valgus angle. Results: Twenty-nine of 39 specimens were considered to have hallux valgus characterized by a hallux valgus angle of 15 degrees or greater. Four of 39 (10%) specimens revealed absence of chondral lesions, and 3 of those were found in the group with a hallux valgus angle of less than 15 degrees. Chondral lesions of increasing size and grade were seen more commonly with a more severe hallux valgus deformity. Particular locations on the metatarsal head appeared to be more prone to cartilaginous lesions when compared to other locations. Conclusion: Assessment of first metatarsophalangeal joint articular damage with regard to hallux valgus may be an important clinical parameter for consideration. Clinical Relevance: Operative intervention to realign the first metatarsophalangeal joint may correct malalignment and relieve pressure on the widened forefoot, but residual pain within the joint may emanate from preexisting articular cartilaginous lesions. These findings support the concept that earlier intervention with operative realignment of a hallux valgus deformity and specifically the sesamoid complex may diminish degenerative changes.