Equinus Correction During Multilevel Surgery in Adults With Cerebral Palsy

The Impact of Operative Correction of Equinus in Cerebral Palsy on Gait Patterns

BACKGROUND

This study aimed to evaluate gait outcomes and strength following the surgical correction of equinus in cerebral palsy (CP) based on different surgical procedures. We included the Baumann and Strayer procedures, as well as the Achilles tendon lengthening (ATL).

METHODS

A retrospective analysis was performed in patients with infantile, bilateral CP who received instrumental 3D gait analysis before and after surgical correction (18.66 months postoperatively). Patients were divided into 3 groups: Strayer surgery, Baumann surgery, and ATL. Gait performance and muscle strengths were compared between studied surgeries.

RESULTS

A total population of 204 patients (15.43 years) with 341 operated lower limbs (LLs) was analyzed. Dorsiflexion in swing and stance phases significantly improved in all groups postoperatively. The Strayer and the ATL group showed higher postoperative dorsiflexion than the Baumann group. However, no loss of strength was observed with the Baumann method. Maximum power improved in this group postoperatively. An 8.2% loss in calf muscle strength was recorded in the Strayer group.

CONCLUSION

Operative pes equinus treatment successfully improved the gait of children and adults with CP postoperatively. There were differences in postoperative results between studied operative techniques regarding range of motion and power.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Quantifying the effects of achilles tendon lengthening surgery: An intraoperative approach

Achilles tendon lengthening (ATL) is frequently used in the treatment of foot deformities. However, there is currently no objective method to determine the optimal muscle length during surgery. We developed an intraoperative approach to evaluate the passive and active forces of the triceps surae muscle group before and after ATL and aimed to test the following hypotheses: 1) the ankle passive range of motion (ROM) increases, 2) passive muscle forces decrease post-ATL, and 3) forces measured from patients with non-neurological and neurological conditions demonstrate different characteristics. Passive forces at various ankle joint positions were measured in ten patients (11.3 ± 3.0 years old) pre- and post-ATL using a force transducer attached to the Achilles tendon. In six patients, active isometric forces were measured by stimulating the triceps surae supramaximally. Passive forces decreased by 94.3% (p < 0.0001), and ROM increased by 89.4% (p < 0.0001) post-ATL. The pre-ATL passive forces were 70.8% ± 15.1% lower in patients with idiopathic foot deformities than in patients with neurological conditions (p < 0.001). The peak active force of 209.8 ± 114.3 N was achieved at an ankle angle of 38.3° ± 16.0°, where the passive force was 6.3 ± 6.7 N. The inter-individual variability was substantial in both groups. In conclusion, the hypotheses posed were supported. The present findings suggest that muscle passive and active force production as well as the inter-individual variability should be considered when planning further treatment.

Reliability and Reference Norms of Single Heel-Rise Test Among Children: A Cross-sectional Study

There is a lack of data regarding the single heel-rise test (SHRT) among children. Hence, we aimed to establish reliability and reference norms of SHRT among children aged 8 to 12 years. About 500 healthy children were randomly selected from the recognized school and community settings. After demographic measurements, SHRT was conducted to evaluate the strength of each plantar flexors. SHRT repetitions were assessed by the same rater on 2 occasions for intrarater (on the same day) and test-retest reliability (on different days) and by 2 raters for inter-rater reliability. Relative reliability was described in terms of the intraclass correlation coefficient (ICC) and Pearson correlation coefficient (r). Absolute reliability was indicated by the standard error of measurement (SEm), minimal detectable change (MDC), and Bland-Altman graph. The mean of the number of repetitions of SHRT was calculated to derive the reference norm of SHRT. The anthropometric parameters were correlated with SHRT for multiple regression analysis. Intrarater, test-retest, and inter-rater reliability of SHRT were, ICC = 0.81, ICC = 0.70, and ICC = 0.57, respectively. The Bland-Altman graph confirmed limits of agreement for intrarater, test-retest, and inter-rater reliability. The reference norm of SHRT is documented to be 20.6 ± 4.8. SEm and MDC are found to be 2 and 3, respectively. Multiple regression analysis predicted a correlation of age, weight, and calf muscle girth with SHRT. SHRT is moderate to good reliable in assessing the strength of plantar flexors. The reference norms of SHRT have been derived for healthy children aged 8 to 12 years.

Defining Equinus Foot in Cerebral Palsy

Background: Equinus foot is the deformity most frequently observed in patients with cerebral palsy (CP). While there is widespread agreement on the treatment of equinus foot, a clear clinical definition has been lacking. Therefore, we conducted this study to evaluate functional changes in gait analysis in relation to maximum possible dorsiflexion (0°, 5°, 10° and 15°) and in two subgroups of CP patients (unilateral and bilateral). Methods: In this retrospective study, CP patients with different degrees of clinically measured maximum dorsiflexion were included. We further subdivided patients into unilaterally and bilaterally affected individuals and also included a healthy control group. All participants underwent a 3D gait analysis. Our goal was to determine the degree of maximum clinical dorsiflexion where the functional changes in range of motion (ROM) and ankle moment and power during gait were most evident. Then, a subgroup analysis was performed according to the affected side. Results: In all, 71 and 84 limbs were analyzed in unilaterally and bilaterally affected subgroups. The clinically 0° dorsiflexion group barely reached a plantigrade position in the 3D gait analysis. Differences in ROM were observed between subgroups. Ankle moment was quite similar between different subgroups but to a lower extent in the unilateral group. All CP patients had reduced ankle power compared to controls. Conclusions: A cutoff value of clinical ≤ 5° dorsiflexion is the recommended value for defining a functionally relevant equinus foot in CP patients.

Gastrocnemius Recession as an Alternative to Midfoot Arthrodesis for Painful Midfoot Arthritis

Arthrodesis has been described as the gold standard of treatment for midfoot degenerative joint disease (DJD) but has also been associated with nonunion, increased tourniquet times, technical difficulty, and a long postoperative non-weightbearing period. Although it is postulated that a contracted gastrocnemius may cause midfoot pain, there are no reports of using the procedure as a primary treatment for midfoot DJD. The purpose of this study was to determine whether gastrocnemius recession resolved midfoot pain from osteoarthritis and eliminated the need for midfoot arthrodesis. Eleven patients with symptomatic midfoot osteoarthritis and gastrocnemius equinus elected to have a modified Baker gastrocnemius recession as an alternative to a recommended midfoot arthrodesis. Patients were kept non-weightbearing for 2 weeks, transitioned to protected weightbearing in a controlled ankle motion walking boot at weeks 3 to 4, and were allowed to ambulate without restriction in regular shoes at 4 weeks. Preoperative American Orthopedic Foot & Ankle Society (AOFAS) midfoot scores were compared with postoperative scores. Eight (72.7%) of the 11 patients responded to the postoperative survey (n = 8). The mean AOFAS midfoot score improved by 44.63 ± 20.9 points (mean ± standard deviation) (range 18 to 76) or 107% (p < .01). All subjects reported sustained improvement since the preoperative evaluation, with a mean time to follow-up of 28 ± 9.9 months (range 12 to 40). None of the patients surveyed underwent subsequent arthrodesis of the midfoot. The results of this investigation indicate that gastrocnemius recession is an effective treatment to relive symptomatic midfoot osteoarthritis. Foot and ankle surgeons may consider this procedure before performing midfoot arthrodesis to treat this pathology.

Recurrence of knee flexion contracture after surgical correction in children with cerebral palsy

PURPOSE

Knee flexion contracture (FC) and crouch gait are challenging to treat in children with cerebral palsy (CCP), and recurrent knee FC after surgery is a severe complication. The aim was to identify factors associated with recurrent knee FC after surgery.

METHODS

The records of 62 CCP (age 10.6±2.6 years) who underwent surgery and were followed for > six months were reviewed. Knee FC was treated by hamstring lengthening, posterior knee capsulotomy, and femoral shortening/extension osteotomy until full extension was obtained. Kaplan-Meier analysis was used to estimate the probability of the correction being maintained. Cox proportional hazard modeling was used to compare parameters between patients with and without recurrent knee FC, with the time to recurrence as the endpoint. Potential confounding factors were included in the multivariate analysis.

RESULTS

In total, the procedure was performed on 122 knees. The average weight-for-age z score was -1.3±1.2. The average follow-up period was 5.4±4.2 years. Knee FC recurrence was observed in 37 knees (30%). The average recurrence-free time was 4.9 years, with most cases of recurrence (33 knees) occurring within six years after surgery. The factors associated with recurrence were age (HR, 1.19) and a required posterior knee capsulotomy procedure (HR, 4.53).

CONCLUSION

Recurrent knee FC after correction is associated with CCP who are older at the time of operation and when posterior knee capsulotomy is performed. The age at operation should be optimized. The sequence of procedures should be performed only as necessary to minimize the chance of post-operative muscle weakness and recurrence.

Effects of soft tissue surgery on transverse kinematics in patients with cerebral palsy

BACKGROUND

Gait disturbances, including flexed knee gait, stiff knee gait, and tip-toeing gait, are common in patients with cerebral palsy (CP). There has been no reports regarding kinematic changes in the transverse plane after soft tissue surgeries, such as distal hamstring lengthening (DHL), rectus femoris transfer (RFT), and tendo-Achilles lengthening (TAL). This study aimed to evaluate changes in the transverse plane after soft tissue surgery in patients with CP by assessing the effects of the DHL, RFT, and TAL.

METHODS

The study enrolled 156 consecutive patients (mean age, 8.4 years; range, 4.4 to 20.9), representing 213 operated limbs, who underwent soft tissue surgery including DHL with semitendinosus transfer, RFT, and TAL. All patients were assessed by preoperative and 1-year postoperative three-dimensional gait analysis. Changes in transverse plane kinematics after soft tissue surgery and affecting factors were analyzed.

RESULTS

Sagittal kinematics including knee flexion at initial contact, ankle dorsiflexion at initial contact, and mean ankle dorsiflexion in the stance phase were significantly improved after single event multilevel surgery (all p < 0.001). Transverse kinematics, including mean tibial rotation and foot progression angle, were significantly improved to a more external angle after soft tissue surgeries (- 2.9°, p = 0.004 and - 9.5°, p < 0.001). The mean hip rotation was significantly improved to a more external angle by RFT (- 4.7°, p = 0.010) and the foot progression angle was significantly improved to a more external angle by TAL (- 3.9°, p = 0.028).

CONCLUSIONS

This study found that the transverse kinematics were improved to a more external angle after soft tissue surgery in patients with CP. Therefore, clinicians should consider that soft tissue surgery can affect the transverse plane kinematics in patients with CP. To confirm our findings, further research regarding the natural history of femoral and tibial torsion in children with CP is needed.

Soft tissue microcirculation around the healthy Achilles tendon: a cross-sectional study focusing on the Achilles tendon and dorsal surgical approaches to the hindfoot

Background

Dorsal approaches to the hindfoot are frequently used. Furthermore, the vascular supply is discussed as a possible cause for ruptures and degeneration of the Achilles tendon. The aim of this study was to evaluate the microperfusion of three possible posterior approaches to the hindfoot and different areas of the Achilles tendon.

Methods

In 111 subjects, a laser Doppler/white light spectroscopy was used to measure microperfusion in terms of blood flow (Flow) and capillary venous oxygen saturation (SO2) in the hindfoot and Achilles tendon. Measurements were performed at two measurement points (MP, proximal and distal) of three dorsal approaches (medial, lateral and central) and inside the Achilles tendon.

Results

Microperfusion differed partially between the surgical approaches. The medial and the lateral approaches were significantly superior to the central approach with regard to Flow in both MP (p <  0.001), while SO2 was significantly higher at the proximal measurement point (MP 1; p <  0.001). In this area, the lateral approach was significantly superior to the medial approach regarding Flow (MP 1; p = 0.012).

The Achilles tendon exhibited a significantly reduced microperfusion 5 cm proximal to the calcaneal tubercle (SO2 p = 0.001; Flow p = 0.048). Demographic factors, such as body mass index and age, had different effects. Microcirculation was partially superior in men and negatively affected by smoking.

Conclusions

Soft tissue microcirculation on the lateral and medial side of the healthy Achilles tendon was better than centrally on the tendon. Proximally, the lateral approach was better than the medial approach. These circumstances could provide advantages regarding the surgical approach. The Achilles tendon exhibited significantly reduced microperfusion at the typical side of degeneration and rupture. This circumstance could be a possible cause of degenerative processes.