Mini Bone Block Distraction Subtalar Arthrodesis (SAMBB) in the Management of Acquired Adult Flatfoot with Subtalar Arthritis: A Modification to the Grice-Green Procedure

Comparison of different surgeries for correction of fixed flatfoot deformity studied through a dynamic model

Different surgeries are used to treat stage III Adult Acquired Flatfoot Deformity. Some include hindfoot manipulation with subtalar fusion (single fusion), triple fusion (subtalar, talonavicular, and calcanealcuboid), and triple fusion with additional midfoot and forefoot manipulation. This study aimed to compare the effect of these surgeries on the unloaded and loaded foot, using a validated dynamic computational model. Five patients with stage III flatfoot underwent pre-surgical and post-surgical CT scans. Dynamic computational models were created for four groups: pre-operative, single fusion, triple fusion, and triple fusion with additional maneuver. A control group was based on models from nine cadaveric normal feet. Once the effect of the surgeries on foot architecture was assessed, the response of the foot to bodyweight was evaluated. All surgeries changed the unloaded foot architecture towards normal. Triple fusion following the additional manipulation produced the best correction, but reduced talonavicular coverage. Under bodyweight, it was observed that, for the triple fusion surgeries, particularly after additional manipulation, foot rigidity and contact forces under the fourth and fifth metatarsal bones increased. Moreover, all surgeries moved the tibiotalar contact position to an area previously reported to have a lower risk of osteoarthritis. Clinical significance: the study results suggest that single fusion surgery corrects the deformity, with less risk of overcorrection, compared to the other techniques. However, triple fusion is necessary when osteoarthritis affects the Chopart joint.

Impact of Subtalar Distraction Arthrodesis on Ankle Joint: Radiological Insights from Modified Grice-Green Procedure

Subtalar distraction arthrodesis (SDA) is a surgical procedure designed to treat hindfoot deformities associated with isolated subtalar joint arthritis. In 1996, Fitzgibbons was the first to observe that, in some cases, hindfoot fusion appeared to be associated with the development of tibiotalar valgus tilt. Since then, few studies have addressed this issue. Given that hindfoot fusion can be performed using various techniques, this study investigated the potential tibiotalar joint frontal or sagittal modifications resulting from the modified Grice-Green technique. All the consecutive patients who underwent the modified Grice-Green procedure were included. The patient records were reviewed to extract demographic data. Weight-bearing foot and ankle radiographs were assessed to measure the talar tilt angle and the tibiotalar ratio on the same picture archiving and communication system by three independent observers. A total of 69 patients met the criteria for inclusion. The mean talar tilt showed no substantial changes, since the increase from 1.46 ± 1.62 preoperatively to 1.93 ± 2.19 at a minimum of 8 months postoperatively was not statistically significant (p = 0.47). The average preoperative tibiotalar ratio significantly increased from 33.4 ± 4.4% to 35 ± 4% postoperatively (p = 0.007), although remaining within the normal range, indicating a possible realignment of the posterior facet of the subtalar joint. In conclusion, this study highlights the effectiveness of the modified Grice-Green procedure in achieving a favorable realignment without impacting the ankle joint, particularly regarding tibiotalar valgus tilt.

Surgical management of clubfoot overcorrection: a case series

INTRODUCTION

Overcorrection is a possible complication of clubfoot treatment, whose prevalence varies from 5 to 67%. Overcorrected clubfoot usually presented as a complex flatfoot with different degrees of hindfoot valgus, flat top talus, dorsal bunion, and dorsal navicular subluxation. The management of clubfoot overcorrection is challenging, and both conservative and surgical treatments are available. This study aims to present our experience in the surgical management of overcorrected clubfoot and to provide an overview of actual treatment options for each specific sub-deformity.

MATERIALS AND METHODS

A retrospective cohort study of patients surgically treated for an overcorrected clubfoot from 2000 to 2015 at our Institution was conducted. Surgical procedures were tailored to the type and symptomatology of the deformity. A medializing calcaneal osteotomy or subtalar arthrodesis was performed for hindfoot valgus. Subtalar and/or midtarsal arthrodesis were considered in cases of dorsal navicular subluxation. The first metatarsus elevatus was addressed through a proximal plantarflexing osteotomy, sometimes associated with a tibialis anterior tendon transfer. Clinical scores and radiographic parameters were obtained pre-operatively and at the last follow-up.

RESULTS

Fifteen consecutive patients were enrolled. The series included 4 females and 11 males, with a mean age at surgery of 33,1 (18-56) years, and a mean follow-up of 4,46 (2-10) years. Seven medializing calcaneal osteotomies, 5 subtalar arthrodesis, 11 first metatarsal plantarflexing osteotomies, and 7 anterior tibialis tendon transfers were performed. A statistically significant improvement in both clinical and radiographic scores was observed.

CONCLUSIONS

Management of overcorrected clubfoot involves many surgical techniques because of the high interpersonal variability of the deformities. The surgical approach showed positive results, as long as the indication is based on clinical symptoms and functional impairment rather than morphological alterations and radiographic findings.

Clinical and multi-segment kinematic analysis of a modified Grice arthrodesis to correct type II adult-acquired flat-foot

BACKGROUND

Adult acquired flat foot (AAFF) is a symptomatic postural alteration of the foot due to modifications in bony structures and/or soft tissues supporting the medial longitudinal arch. For the most severe cases, when orthotic solutions do not provide enough pain relief, surgery may be necessary.

RESEARCH QUESTION

Is it possible to restore a normal medial longitudinal arch and to correct the static and dynamic frontal plane alignment of the rearfoot via a modified Grice surgical procedure in AAFF patients?

METHODS

Eleven patients with stage II AAFF were recruited in the study and underwent the Grice procedure. Patients were assessed via gait analysis using a validated multi-segment foot protocol. Double-leg standing static posture and foot joint kinematics during barefoot walking were measured before surgery and at a mean follow-up of 15 ± 8 months. Twenty-seven age-matched healthy subjects without foot morphological alterations were used as control. Patients' feet were clinically assessed via the Foot Function Index and the Foot Posture Index. Wilcoxon signed rank test was used to assess differences in kinematic and spatio-temporal parameters between pre-op and follow-up evaluations. 1D statistical parametric mapping was used to assess differences in temporal profiles of foot joint rotations.

RESULTS

The clinical indexes significantly improved at post-op (p < 0.05). No differences in sagittal plane static and dynamic joint rotations were observed between pre-op and post-op. In the frontal plane, metatarsus to calcaneus and midfoot to calcaneus rotation angles significantly improved from pre-op to post-op, with the latter resulting consistent with control data. Range of motion and maximum value of the medial longitudinal arch angle were reduced following surgery.

SIGNIFICANCE

The modified Grice procedure restored a good frontal-plane alignment of rearfoot and midfoot, and the clinical scores provided evidence of its effectiveness in significantly reducing pain and improving the quality of daily activities.

3D measurement techniques for the hindfoot alignment angle from weight-bearing CT in a clinical population

Cone-beam CT (CBCT) scans now enable accurate measurements on foot skeletal structures with the advantage of observing these in 3D and in weight-bearing. Among the most common skeletal deformities, the varus/valgus of the hindfoot is the most complex to be represented, and a number of measure proposals have been published. This study aims to analyze and to compare these measurements from CBCT scans in a real clinical population with large such deformity. Ten patients with severe acquired adult flatfoot and indication for surgery underwent CBCT scans (Carestream, USA) while standing on that leg, before and after surgical correction. Corresponding 3D shape of each bone of the distal shank and hindfoot were defined (Materialise, Belgium). Six different techniques from the literature were used to calculate the varus/valgus deformity, i.e. the inclination of the hindfoot in the frontal plane of the shank. Standard clinical measurements by goniometers were taken for comparison. According to these techniques, and starting from a careful 3D reconstruction of the relevant foot skeletal structures, a large spectrum of measurements was found to represent the same hindfoot alignment angle. Most of them were very different from the traditional clinical measures. The assessment of the pre-operative valgus deformity and of the corresponding post-operative correction varied considerably. CBCT finally allows 3D assessment of foot deformities in weight-bearing. Measurements from the different available techniques do not compare well, as they are based on very different approaches. It is recommended to be aware of the anatomical and functional concepts behind these techniques before clinical and surgical conclusions.

Grice extra-articular subtalar fusion for spastic pes planovalgus

INTRODUCTION

A pes planovalgus deformity, an unstable foot deformity, affects the gait of children with cerebral palsy (CP). Treatments, including subtalar fusion, were proposed. The Grice procedure maintains foot stability, but bone graft non-union poses a challenge. This study aimed to identify the rate and factors related to post-operative bone graft non-union.

METHODS

Thirty-one paediatric CP patients (age, 8.9 ± 1.8 years) who underwent the Grice procedure (53 feet) using ipsilateral tibial bone grafts were reviewed. Pre-operative gross motor function classification system (GMFCS) classes were class 1 in five, 2 in five, 3 in 14, and 4 in seven patients. Standing foot radiographs were assessed for signs of non-union, and parameters (talocalcaneal and talar declination angles and talar head uncovering index) measured pre-operatively, post-operatively, and at the most recent evaluation were compared. Factors associated with bone graft non-union were analysed by regression analysis. P < 0.05 was considered statistically significant. Degenerative changes in hindfoot joints were evaluated by Bargon's criteria.

RESULTS

At the average follow-up evaluation at 5.4 ± 4.3 years, the GMFCS class was improved or was maintained in 29/31 patients. Post-operative radiographic measurements were restored and were maintained over the follow-up period (P < 0.001). A total of 14/53 feet (26%) had non-union. The pre-operative lateral talocalcaneal angle (OR 1.08, p = 0.04) and follow-up duration (OR 1.18, p = 0.03) were identified in univariate analysis as potential factors related to non-union but were not confirmed in a multivariate model. Hindfoot joints in most feet showed mild degenerative changes.

CONCLUSION

Grice subtalar fusion in patients with a higher pre-operative lateral talocalcaneal angle might lead to bone graft non-union.

Angular and linear measurements of adult flexible flatfoot via weight-bearing CT scans and 3D bone reconstruction tools

Acquired adult flatfoot is a frequent deformity which implies multiple, complex and combined 3D modifications of the foot skeletal structure. The difficult thorough evaluation of the degree of severity pre-op and the corresponding assessment post-op can now be overcome by cone-beam (CBCT) technology, which can provide access to the 3D skeletal structure in weight-bearing. This study aims to report flatfoot deformities originally in 3D and in weight-bearing, with measurements taken using two different bone segmentation techniques. 21 such patients, with indication for surgical corrections, underwent CBCT (Carestream, US) while standing on one leg. From these scans, 3D models of each bone of the foot were reconstructed by using two different state-of-the-art segmentation tools: a semi-automatic (Mimics Innovation Suite, Materialise, Belgium), and an automatic (Bonelogic Ortho Foot and Ankle, Disior, Finland). From both reconstructed models, Principal Component Analysis was used to define anatomical reference frames, and original foot and ankle angles and other parameters were calculated mostly based on the longitudinal axis of the bones, in anatomical plane projections and in 3D. Both bone model reconstructions revealed a considerable valgus of the calcareous, plantarflexion and internal rotation of the talus, and typical Meary’s angles in the lateral and transverse plane projections. The mean difference from these angles between semi-automatic and automatic segmentations was larger than 3.5 degrees for only 3 of the 32 measurements, and a large number of these differences were not statistically significant. CBCT and the present techniques for bone shape reconstruction finally provide a novel and valuable 3D assessment of complex foot deformities in weight-bearing, eliminating previous limitations associated to unloaded feet and bidimensional measures. Corresponding measurements on the bone models from the two segmentation tools compared well. Other more representative measurements can be defined in the future using CBCT and these techniques.

Outcome After Modified Grice-Green Procedure (SAMBB) for Arthritic Acquired Adult Flatfoot

BACKGROUND

Adult acquired flatfoot deformity is a well-known and recognized cause of pain and disability. The purpose of this retrospective study was to describe radiographic and clinical outcomes of the modified mini bone block distraction subtalar arthrodesis (SAMBB) in adult patients affected by adult flatfoot with subtalar joint osteoarthritis at a midterm mean follow-up.

METHODS

A retrospective review of our database identified patients. Radiological imaging was used to evaluate angular corrections (Meary's angle [MA], talar coverage angle [TC], and calcaneal pitch angle [CP]) to assess the rate of union and highlight the possible progression of arthritis in nearby joints. Clinical evaluation was performed at the time of surgery and at the final follow-up using the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score. Sixty-two feet were evaluated at a mean follow-up of 6.2 ± 4.2 years.

RESULTS

The AOFAS score improved from a mean value of 48.1 ± 6.1 to a postoperative average score of 87.7 ± 5. CP, TC, and MA showed a postoperative improvement to 17.7 ± 2.1, 2.9 ± 0.7, and 0.6 ± 0.6 degrees, respectively, at the final follow-up, and all deformities were corrected. Five complications (8%) were reported: 1 major and 4 minor. No graft reabsorption, sural nerve neuralgia, or donor site morbidity was recorded.

CONCLUSION

To our knowledge, this study is the first report of a modified Grice-Green technique (SAMBB) that is a safe and effective treatment of flatfoot in the adult with subtalar arthritis.

LEVEL OF EVIDENCE

Level IV, retrospective case series.