Using Three-Dimensional Gait Data for Foot/Ankle Orthopaedic Surgery

We present the case of a forty year old male who sustained a torn carotid during strenuous physical activity. This was followed by a right hemispheric stroke due to a clot associated with the carotid. Upon recovery, the patient’s gait was characterized as hemiparetic with a stiff-knee pattern, a fixed flexion deformity of the toe flexors, and a hindfoot varus. Based on clinical exams and radiographs, the surgical treatment plan was established and consisted of correction of the forefoot deformities, possible hamstrings lengthening, and tendon transfer of the posterior tibial tendon to the dorsolateral foot. To aid in surgical planning, a three-dimensional gait analysis was conducted using a state-of-the-art motion capture system. Data from this analysis provided insight into the pathomechanics of the patient’s gait pattern. A forefoot driven hindfoot varus was evident from the presurgical data and the tendon transfer procedure was deemed unnecessary. A computer was used in the OR to provide surgeons with animations of the patient’s gait and graphical results as needed. A second gait analysis was conducted 6 weeks post surgery, shortly after cast removal. Post-surgical gait data showed improved foot segment orientation and position. Motion capture data provides clinicians with detailed information on the multisegment kinematics of foot motion during gait, before and during surgery. Further, treatment effectiveness can be evaluated by repeating gait analyses after recovery

The Influence of Patient Factors on the Outcome of Synthetic Cartilage Implant Hemiarthroplasty versus First Metatarsophalangeal Joint Arthrodesis

Category: Midfoot/Forefoot Introduction/Purpose: Many studies have compared the outcomes of MTPJ1 hemiarthroplasty and arthrodesis, but there is a paucity of data on the influence of patient factors on clinical outcomes. A prior prospective, randomized, clinical trial compared the efficacy and safety of first metatarsophalangeal joint (MTPJ1) hemiarthroplasty with a synthetic polyvinyl alcohol hydrogel implant (Cartiva®) and MTPJ1 arthrodesis for moderate to severe hallux rigidus. The current study evaluated the data from this clinical trial to determine the impact of numerous patient variables, including osteoarthritis grade, hallux valgus angle, preoperative range of motion (ROM), gender, body mass index (BMI), preoperative duration of symptoms, and preoperative pain level, on the success or failure of MTPJ1 hemiarthroplasty and arthrodesis. Methods: Patients =18 years diagnosed with hallux rigidus grade 2, 3, or 4 were randomized and treated with synthetic cartilage implant MTPJ1 hemiarthroplasty (n=129) or arthrodesis (n=47). Outcome measures included a pain visual analogue scale (VAS), Foot and Ankle Ability Measure (FAAM) Sports and Activities of Daily Living (ADL) scores, and Short Form-36 Physical Functioning (SF-36 PF) subscore, obtained preoperatively and at 2, 6, 12, 24, 52 and 104 weeks postoperatively. Great toe active dorsiflexion motion, secondary procedures, radiographs and safety parameters were evaluated. A patient’s outcome was deemed successful if composite primary endpoint criteria for clinical success (pain, function and safety) were met at 24 months. Predictor variables included: osteoarthritis grade; hallux valgus angle; preoperative ROM; gender; body mass index (BMI); preoperative symptom duration; prior surgery; and preoperative pain level. Two-sided Fisher’s Exact test was used to assess the impact of these variables on success of surgery (p0.05) in success rates (i.e., VAS pain reduction ≥ 30%, maintenance/improvement in function, freedom from radiographic complications, and no secondary surgical intervention) between synthetic cartilage implant MTPJ1 hemiarthroplasty and arthrodesis when stratified by osteoarthritis grade, degree of preoperative hallux valgus, extent of preoperative ROM, gender, BMI, duration of symptoms, prior MTPJ1 surgery status, and preoperative pain VAS score (Table 1). Notably, patients with minimal ROM and mild hallux valgus had equivalent success rates for both procedures. Males tended to have greater clinical success with implant hemiarthroplasty versus arthrodesis, but this difference was not statistically significant. 1Baumhauer et al., FAI, 2016;37(5):457-69. Conclusion: Synthetic cartilage implant hemiarthroplasty is an appropriate treatment for patients with hallux rigidus of Coughlin grade 2, 3 or 4. Its results in those with associated mild hallux valgus (<20 degrees) and in those with a high degree of preoperative stiffness are equivalent to MTPJ1 fusion, irrespective of gender, BMI, osteoarthritis grade, or preoperative pain or duration of symptoms, in contrast to what might have been expected

2017 Roger A. Mann Award Winner

Category: Midfoot/Forefoot Introduction/Purpose: Hallux rigidus (HR) is a very common symptomatic problem affecting one in 40 patients over the age of 50 years. A variety of treatment options exist and, as is common in surgery, grading systems are used to assess severity of the condition and aid in the guidance of treatment. The most commonly used grading system for HR uses radiographic images, great toe range of motion and clinical symptoms. This study examines the relationship of radiographic and motion findings to observed intra-operative cartilage loss in patients with HR and explores hallux rigidus grade and cartilage loss as predictive variables for treatment outcomes. Methods: A prospective, randomized non-inferiority study examining outcomes of arthrodesis compared to hemiarthroplasty of the first metatarsal phalangeal joint (Cartiva®) was performed.2 All randomized and treated patients were included in this study. Patients underwent pre-operative clinical examination, including measures of joint motion, radiographic assessment and HR grade. Operatively, observations of cartilage loss on the metatarsal head and opposing proximal surfaces were recorded. All patients’ data, irrespective of treatment, were aggregated and Spearman Rank Correlation coefficients used to assess for strength of correlation of active peak dorsiflexion and cartilage loss to HR grade. Outcomes data were then separated by treatment group and two-sided Fisher’s Exact test assessed these variables’ impact on clinical success (p<0.05). Results: In 202 patients, 59 (29%), 110 (55%), and 33 (16%) were classified as Coughlin1 Grades 2, 3, and 4, respectively. There was no correlation between grade and active peak dorsiflexion (-0.02, p=0.78). While rank correlations between grade and cartilage loss on the proximal phalanx and metatarsal head statistically significantly differed from zero, the magnitudes of the correlations were small, 0.176 (p=0.01) and 0.224 (p=0.001), respectively (Table 1). Among Grade 4 patients, 36.4% had no metatarsal cartilage remaining; but this was also found in 8.5% of Grade 2 patients. Similarly, 52.5% of Grade 2 patients had ≥50% metatarsal cartilage remaining; but this was also found in 21.2% of Grade 4 patients. None of the observed factors were significantly associated with likelihood of achieving composite success. Conclusion: This study examines the relationship of motion and intra-operative cartilage loss findings with a commonly used clinical and radiographic grading system for hallux rigidus. This study population included only candidates with HR considered a candidate for arthrodesis based on review of clinical symptoms however the Grade assigned maybe Coughlin Grade 2, 3 or 4. Irrespective of the Grade, positive outcomes were demonstrated within both treatment groups. The weak correlations of preoperative motion and intra-operative cartilage loss to grade suggests that clinical symptoms should be a significant determinant guiding the treatment option rather than radiographic or range of motion factors

Five-year Outcomes of a Synthetic Cartilage Implant for the First Metatarsophalangeal Joint in Advanced Hallux Rigidus

Category: Midfoot/Forefoot Introduction/Purpose: Hallux rigidus is the most common arthritic condition of the foot. A prospective, randomized, non-inferiority clinical trial of first metatarsophalangeal joint (MTPJ) hemiarthroplasty with a synthetic polyvinyl alcohol hydrogel implant, for moderate to severe hallux rigidus, demonstrated maintenance of MTPJ active dorsiflexion motion and excellent pain relief; additionally, the trial showed functional outcomes and safety equivalent to first MTPJ arthrodesis at 24 months (Baumhauer et al. 2016; FAI:37(5):457-469). Recognizing that many hemiarthroplasty and total toe implants have initially good results that deteriorate over time, the purpose of this study was to prospectively assess the safety and efficacy outcomes for the synthetic cartilage implant population and to determine if the excellent outcomes were maintained at >5 years. Methods: One hundred and fifty-two patients underwent implant hemiarthroplasty in the original trial; 14 underwent implant removal and conversion to fusion and 3 were lost to follow-up during the first 24 months, leaving 135 eligible for this study. One hundred patients were evaluated at 5+ years; 5 could not be reached for follow-up. Thirty are pending consent, follow-up, and/or data entry; their status will be available for inclusion at the conference presentation. Patients completed a pain visual analogue scale (VAS) and Foot and Ankle Ability Measure (FAAM) Sports and Activities of Daily Living (ADL) scores, preoperatively and at 2, 6, 12, 26, 52, 104 and 260 weeks postoperatively. Minimal clinically important differences are: =30% difference for pain VAS, 9 points for FAAM Sports, and 8 points for FAAM ADL. Great toe active dorsiflexion, weight-bearing radiographs, secondary procedures, and safety parameters were evaluated. Results: Of 100 synthetic cartilage implant hemiarthroplasty patients available at mean 5.8 years follow-up (SD ±0.7; range: 4.4- 7.4), 5 underwent implant removal and conversion to fusion in years 2-5 (Figure 1), and 2 underwent subsequent surgical interventions during the pivotal trial and were censored, leaving 93 patients for evaluation. Pain and function outcomes observed at 5.8 years were similar to those at 2 years (Figure 1). VAS Pain and FAAM Sports Scores were maintained or improved at 5.8 years follow-up, but these differences were not clinically significant. Joint motion was maintained at 5.8 years. No evidence of avascular necrosis, device migration or fragmentation was observed upon independent radiographic review. Eighty-six percent of patients agreed their overall well-being had improved, and 92% would have the procedure again. Conclusion: Clinical and safety outcomes of patients having undergone synthetic cartilage implant hemiarthroplasty for the surgical treatment of hallux rigidus were previously demonstrated to be non-inferior to the gold standard treatment, MTPJ fusion, at 2 years. Prospectively determined outcomes for 100/135 of these implant hemiarthroplasty patients at 5.8 years are similar to those reported at 2 years. Longer-term results demonstrate that clinical and safety outcomes for synthetic cartilage implant hemiarthroplasty are durable, and that the implant remains a viable treatment option to decrease pain, improve function and maintain motion for advanced hallux rigidus