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EXTENSIVE POSTEROMEDIAL RELEASE IN CLUB FEET - An Experience with 54 Patients

Binoti A Sheth, Vishal Sarwahi, Mg Yagnik
Dept. of Orthopaedics, Bai Jerbai Wadia Hospital for Children, Parel, Mumbai - 400 012.

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Fifty four patients with idiopathic club feet were treated by extensive posteromedial release. The patients were followed for a minimum of one year after operation. Clinical and radiological evaluation was done and compared with a similar procedure, and complete subtalar release reported in other series. The roles of internal fixation and subjective evaluation of result are discussed. The need for a standard scoring system is emphasised to allow comparison between various treatment modalities.

INTRODUCTION

Treatment of clubfoot is controversial. It ranges from proper manipulation, casting, tenotomy of tendo achilles with 90% success as reported by Ponseti, to the thesis that the conservative method of treating CTEV is open surgery, with only 5-10% success by casting and manipulation and that too in the mild form.

MATERIAL AND METHODS

At the BJ Wadia Hospital for Children, patients who underwent extensive posteromedial release minimum one year ago were evaluated. Only patients with idiopathic CTEV, previously untreated and less than two years in age were included in the study.

All feet were initially treated by serial long leg plaster of paris cast up to the age of 5 months or 3-4 cast sittings. After it was determined that conservative treatment will not help further, extensive posteromedial release was carried out. This included lengthening of tendo achilles, tibialis posterior, flexor digitorum longus and flexor hallucis longus and release of talonavicular, ankle and subtalar joint capsules. Lateral structures (calcaneofibular ligament, subtalar and ankle joint capsule, superior peroneal retinaculum) were released through medial approach only. At this point if it was felt that calcaneal derotation is not sufficient, a formal lateral release was done, followed by sectioning of medial half of talocalcaneal ligament if thought necessary.

No K wires were used to stabilise the reduction. Wound was closed with minimal tension and first post-op. cast was given in under correction. Weekly casts were changed under anaesthesia to manipulate the foot in neutral to dorsiflexion, without jeopardising the wound closure. Thereafter casts were changed 2-3 weekly to obtain and maintain correction. Sutures were removed at the end of 3-4 weeks. Casts were kept for a minimum of 6 weeks post surgery. Thereafter night splints and shoes were provided and active physiotherapy was started.

Feet were evaluated clinically and radiologically in detail as outlined by Simons [3] (Tables 1 and 2). Clinical evaluation consisted of 9 criteriae. An unsatisfactory result in any category meant an unsatisfactory result overall. Radiological evaluation was done on 6 parameters using a standardised technique for X-rays. Standing or stress AP and lateral X-rays were taken preoperatively and at varying intervals post operatively.

 

TABLE 1 Clinical evaluation
	Satisfactory	Unsatisfactory
• Symptoms	None	Mild to servere pain with normal activity
• Appearance of the hind part of the foot	Normal, or mild deformity Zero to +1	moderate to significant residual deformity, +2 to +4
• Adduction of the fore part of the foot	None to +2	+2 to +4
• Foot-knee malalignmentZero to +1	None to +1	+2 to +4
• Functional weakness of the calf (when possible to test)	None to +1 weakness, weight supported on toes	+2 to +4, cannot support weight on toes
• Range of motion of the ankle	Dorsiflexion > 10 degrees, plantar flexion > 15 degree	Dorsiflexion < 10 degrees, plantar flexion ankle < 15 degree
• Subtalar joint	+3 to +1	Zero
• Additional treatment needed	None, cast, or minor surgery of fore part of foot	Frequent treatment with a case or major reconstructive procedure necessary
• Complications	None to two minor complications, no major complications	One or more major complications

 

TABLE 2 Radiographic evaluation
Radiographic Measurement	Determination	Satisfactory Range	Unsatisfactory Range
Anteroposterior radiograph	Varus angulation of hind part of foot	> 15o	< 15o
• TC angle (evaluationTC divergence)	Valgus angulation of hind part of foot	< 50o	> 50o
•Talocacaneal divergence	Varus angulation of hind part of foot	Zero or -1	-2 or -3
	Valgus angulation of hind part of foot	Zero or +2	+3 or -4
• Navicular position ossified navicular	Medial or lateral talonavicular	-1 or +2	-2,-3,-4,+3 or +4
• Unossified navicular	Medical or lateral talonavicular	-1 to +1	-2,-3,+2 or +3
Ossified navicular	subluxation
Lateral radiograph
•Navicular position Ossified navicular Unossified navicular	Dorsal talonavicular subluxation Dorsal talonavicular subluxation	Not dorsal or +1 Zero or +1	+2 or +3 +2 or +3
•Calcaneus-first metatarsal angle	Carvus angulation Flat foot	> 135o < 170o	< 135o > 170o
• Talocalcaneal angle	Varus angulation Valgus Angulation	> 25o < 60o	< 25o > 60o

Measurement of these parameters slightly out of normal value was considered comparable with excellent clinical results, as advised by Thompson et al. [1]Any foot that had one or more unsatisfactory angle was graded unsatisfactory overall.

To confirm our findings, we also evaluated these facts on scoring system proposed by Ramyantsev et al which is a clinico radiological rating system with 150 points total indicating a normal foot. We found this scoring system to be too detailed and difficult to apply in younger patients.

RESULTS

The clinical results were satisfactory in 74% cases (40 feet) (Figs. 1 and 2) compared to 50% in Simons series of patients which underwent procedures other than complete release. 72% of Simons patients with complete subtalar release had satisfactory results.

Fig 1 :	Child standing on well-corrected feet after extensive postermedial release.

 

Fig2 :	Good correction of the club feet allowing the child to squat.

 

Radiological evaluation (Figs 3 and 4) showed difference in measurement of angles, between preoperative and postoperative X-ray on all criteriae (Table 3). 34 feet (62.9%) had satisfactory results on all 6 parameters. In comparison, Simons showed 64% satisfactory result in patients with complete subtalar release, while patients who underwent other surgical releases showed only 46% satisfactory measurement on all the 6 radiological criteriae. Of these 6 criteriae, only 3; the AP and lateral TC angle and the AP navicular position have been shown to have significant improvement after complete subtalar release in comparison with other procedures.3 In our study the mean change in these angles as shown in Table 3 are 12o, 4o and 30o for TC angle on AP, AP navicular position and lateral TC angle respectively. These compare well with those reported for complete subtalar release in Simons study.

Fig 3:	Lateral stress dorsiflexion and plantar flexion.

 

Fig 4:	X-rays of the feet after surgical correction showing satisfactory Talo-calcaneal angle.

 

Table 3 Changes in measurement of angles of Pre-op and Post-op X-rays
Angle	Mean change
AP XR
TC Angle	12 degrees
navicular position	4 degrees
Lateral XR
TC Angle	30 degrees
Number of satisfactory angles	Feet(/%)
6	34 (62.9%)
5	12 (22.2%)
4	7 (12.9%)
3	1 (1.8%)

 

The average range of motion of ankle joint on X-ray was 36.8o (range 12-56o) in comparison with 34.2o reported by Ramyantsev et al [5] Ankle motion is crucial for our patients due to their need to squat. We also evaluated our result on rating system proposed by Ramyantsev et al [5]. There were 29.4% excellent, 51.2% good, 11.2% fair, and 8.1% poor results in our series. Complete subtalar release results in their experience yielded 22.2% excellent, 46.8% good, 27.3% fair and 3.7% poor results.

COMPLICATION

Serious wound problems occurred in 2 feet over the postero medial aspect of foot. This was evident on first cast change. The feet were maintained in the corrected position and wound was allowed to heal in this position. Varus of hind part of foot was seen in 4 cases, while valgus of > 10o was evident in 6 cases and was associated with intoeing gait. Calcaneus gait was seen in only 2 cases, probably because we sutured tendo achilles in a maximum of 10o dorsiflexion.

Four of these 6 cases with valgus over correction had lateral talonavicular subluxation which believed to be present because naviculo - calcaneo - cuboid complex moves together as one unit with respect to talus. No feet with dorsal union and avascular necrosis of talus were seen.

DISCUSSION

McKay [6] gave the concept of subtalar rotation and thereafter several authors [3-5,8,11,13] have supported release which allows proper and congruous reduction of the joint. As pointed out by Ponseti, however the distorted joints are not congruous and internal fixation is necessary to maintain normal alignment. Scar tissue formed after release provides stability upon removal of K wires and thus increased stiffness is observed after such radical procedures. This has the potential to compromise the functional range of motion. Also observed is the complication of over correction, neither is the rate of recurrence decreased after these procedures. [7]

Extensive PMR with or without internal fixation provides satisfactory correction of deformity with functional results almost as good as the results of successful manipulation. In our evaluation of 54 cases, the functional and radiological results were as good as those in Simons series of complete subtalar release. Also our results are comparable with those of Ramyantsev et al, when evaluated on their scoring system. This indicates that an extensive PMR functionally and radiologically produces results similar to the complete subtalar release. The release of lateral tight structures from within the subtalar and ankle joints, through the posteromedial incision, provides adequate derotation of calcaneum and allows proper reduction. This releases the calcaneofibular ligament, lateral capsule and medial half of peroneal tendon sheath at subtalar joint level. While it may not be possible to release the posterior tibiofibular ligament, the concept of sectioning it is controversial with McKay and Simon holding opposite views. Also the opinions on sectioning talocalcaneal ligament is controversial; of which we release the medial half in case of failure to achieve complete derotation. A formal lateral release is preferred in cases of inability to achieve derotation prior to sectioning talocalcaneal ligament.

There appears to be little correlation between radiographs and function in an operated CTEV. Laaveg and Ponseti1 found that range of motion of ankle and lateral talocalcaneal angle correlate with functional score. Hassbeek and Wright8 found only lateral TC angle to correlate with function on multiple linear regression analysis. In our study also, we have made observations similar to those by Laaveg and Ponseti. It is difficult to standardise a satisfactory result on the basis of ankle range of motion, because of lack of agreement on its functional range. Simons indicates 25o, while McKay suggested > 35o as satisfactory result. Stauffer et al.9 reported ROM during stance as 24.4o while Brougham and Nicol10 emphasized on the components of ankle ROM. In our set of patients, ability to squat is important and thus a plantigrade foot with dorsiflexion of 25o or more was considered satisfactory. We have also observed that postoperative manipulation of foot at cast change produces increased range of ankle motion.

In 1975, Bjonness [11] observed that "the patient is the final judge of whether he has a good foot". However we have seen a number of patients with result graded satisfactory but decreased motion and compromised function in comparison with normal feet. Similar observation was also noted by Haasbeck et al [8] in patients with unilateral clubfoot. Thus, we feel that subjective evaluation of patient can be misleading and a composite scoring system which incorporates objectivity also will enable better analysis and comparison of results. A standardisation of pre-treatment scoring system of club feet must also be done to allow comparative assessment of results of various treatment.

Management of club foot depends on the surgeon’s philosophy which may vary from the conservative approach to radical release. Absence of universally accepted assessment system of CTEV compounds this problem. It is best to individualise the cases and give a fair trial of conservative treatment before attempting surgery. It is also imperative to remember what Porter [12] said, ‘Failure of clubfoot correction rests in surgeon’s hands, not in the child’s foot’.

REFERENCES

1. Laaveg SJ, Ponseti IV. Long term results of treatment of congenital club foot. J Bone and Joint Surg Jan., 1980; 62-A : 23-30.
2. Tachdjian MO. Paediatric orhtopaedics. Philadelphia : WB Saunders. 1990; 2087.
3. Simons GW. Complete subtalar release in club feet Part II. J Bone and Joint Surg September 1985; 67-A : 1056-65.
4. Thompson GH, Richardson AB, Westin GW. Surgical management of resistant congenital talipes equino varus deformities. J Bone and Joint Surg June 1982; 64-A : 652-65.
5. Ramyantsev NJ, Ezrohi VE. Complete subtalar release in resistant clubfeet : A critical analysis of results in 146 cases. J Paediatr Orthopaedics July 1997; 17 : 490-5.
6. McKay DW. New concept of and approach to clubfoot treatment : section II : evaluation and result. J Paediatr Orthop 1983; 3 : 141-8.
7. Ponseti IV. Treatment of congenital club foot : current concepts review. J Bone and Joint Surg March 1992; 74-A : 448-54.
8. Hassbeck JF, Wright JG. A comparison of the long term results of posterior and comprehensive release in the treatment of clubfoot. J Paed Ortho 1997; 17 : 29-35.
9. Stauffer RN, Chao EYS, Brewsterm RC. Force and motion analysis of the normal, diseased and prosthetic ankle joint. Clin Ortho 1977; 127 : 189-96.
10. Brougham DI, Nicol RD. Use of the cincinnati incision in congenital talipes equinovarus. J Paediatr Orthop 1988; 8 : 696-8.
11. Bjonness T. Congenital clubfoot. Acta Orthop Scand 1975; 46 : 848-56.
12. Porter RW. Congenital talipes equino varus : II : a staged method of surgical management. J Bone Joint Surg (B) 1987; 69 : 826-31.

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