Hammer or claw toe
Except in a congenital deformity, the cause of this deformity is usually hallux valgus. We made a study on 200 feet showing that secondary ham- mertoe due to hallux valgus does generally not appear before 40 years. In fact, we distinguish four phases in the hallux valgus chronology.
First, there is a painful bunion.
Secondly, the bunion is less or not painful, because of the medial displacement of the head which leaves the medial dorsal nerve laterally.
Thirdly, patients consult for secondary effects of the bunion, in most cases hammertoe, or metatar- salgia. This phase occurs between 40 and 60 years.
The correction of hallux valgus does not change the hammertoe deformity, so that we have to perform a local treatment.
In most cases the soft tissue procedure combined with axial K-wiring of the toe ensures the ham- mertoe correction. The chronological surgery steps are detailed Fig. 19b-c-d, and Fig. 36b2, b3, b5.
PIP surgery: Resection arthroplasty has to be avoided because of the painful postoperative period and unpredictable long-term results.
Fig. 36a1. Second ray pathology – The three types of second ray pathology:
Metatarsalgia – Hammertoe – MTP dislocation.
Fig. 36a2. Second ray pathology – Chronology of hammertoe deformity combined with hallux valgus.
Study on emerging second hammertoe in the hallux valgus evolution (200 feet).
1. Before 40 years, almost no hammertoe.
2. Emerging of the hammertoe after 40 years.
We distinguish three kinds of second ray patho- logy: claw or hammertoe, metatarsalgia, MTP dislocation.
The Second Ray Pathology
When the hammertoe is rigid, PIP fusion is a good solution. But in fact, in most cases we can correct the deformity with PIP joint preserva- tion (Fig. 36b3). It is the PIP plantar release.
Middle phalanx osteotomies: when the toe is too long, a good solution is the middle phalanx osteotomies. We use either the distal resection (mallet finger, impaired DIP joint) ie DIP arthroplasty or, preferably, the shaft resection i.e.
(SRMP), which preserves the joints (Fig. 36b4):
only point required: the middle phalanx has to be long enough.
Weil osteotomy: Single second metatarsal osteotomy may be performed when the condi- tion is an elongated second metatarsal compared to the first metatarsal (dorso-plantar X-ray view) and to the third metatarsal (medial oblique X-ray view). In other types, we have to perform also the Weil osteotomy in the third and some- times the other lesser rays.
In every case, the correction of a hammertoe needs a temporary toe, axial K-wiring and extensor lengthening.
Fig. 36b1. Second ray pathology – Hammertoe and hallux valgus correction.
Even if the second hammer claw toe is due to the hallux valgus deformity, the correction of hallux valgus does not change the hammertoe which needs a special surgery.
Fig. 36b2. Second ray pathology – Hammer/claw toe correction: Chronological steps MTP Joint.
1. Chronological steps.
2, 3, 4. MTP release 2: the loss of passive MTP plantar flexion requires MTP release. 3. Release by open proce- dure. 4. Per cutaneous release.
Fig. 36b3. Second ray pathology – Hammer/claw toe: Proximal interphalangeal (PIP) surgery.
1, 2. The resection arthroplasty is not a reliable procedure for the second toe. The toe remains swollen and painful for a long time. Long term results are sometimes a disaster.
3. When the deformity is strongly fixed, PTP fusion is a good solution. Fixation by temporary K wiring (one month).
4, 5, 6, 7. The PIP joint seems to be rigid: in fact, in most cases the correction may be made with joint
preservation: (4) Correction by only manipulation: the dorsal flexion must to be free up to 45°. 6, 7 correction by PIP plantar release which is a very good procedure.
8. Temporary K wiring.
Fig. 36b4. Second ray pathology – Hammer/claw toe correction: middle phalanx surgery.
1. The toe is too long. 2. Assessment of the middle phalanx length. 3. Distal resection (DIP arthroplasty), see also Fig. 29e1. 4. Shaft resection (SRMP), see also Fig. 29e2.
Fig. 36b6. Second ray pathology – Hammer / claw toe: Weil metatarsal osteotomy.
1, 2. Single Weil osteotomy is indicated if there is an excess of the second metatarsal length both on dorso- plantar (1) and the medial oblique (2) X-ray views. The shortening of the second metatarsal has to be assessed preferably on the medial oblique view: After the surgery, the third metatarsal must not be too long, but we have to avoid generally this isolated weil osteotomy.
3. The Weil osteotomy has to be combined with the toe K-wiring.
4, 5. If the excess of the second metatarsal length is not significant (comparatively to the third metatarsal) on the medial oblique view, the Weil osteotomy has to be made on the other lesser metatarsals. This is our prefered method.
6. If there is an important excess of the second toe length, the toe itself has to be shortened (see Fig. 36b4), in addition to the Weil osteotomy, because a too long second toe remaining is not well tolerated.
Fig. 36b5. Second ray pathology – Hammer/claw toe correction: Lengthening of the extensor tendon.
1, 2. The axial K-wiring emphasizes the need to perform the extensor tendons lengthening.
3. Lengthening by open procedure.
4. Percutaneous lengthening (as soon as possible).
Metatarsalgia
To relieve the second ray metatarsalgia we have three solutions :
1. Lowering the first metatarsal, which is possible with scarf osteotomy when the inter - metatarsal angle is sufficient.
2. Shortening the second metatarsal by Weil
osteotomy: The same conditions are necessary as for second hammertoe. In both cases, the proximal sliding has to be slight, so as not to result in transfer metatarsalgia to the third ray.
3. BRT second metatarsal elevation osteo- tomy, in cases where there is no indication nor possibility of lowering the first metatarsal or of Weil osteotomy on the second ray.
Fig. 36c1. Second ray pathology – Metatarsalgia: (1) lowering of the first metatarsal.
1. When the intermetatarsal angle is large, we can have a large lowering with the scarf osteotomy, thanks to the lateral plantar obliquity of the cut. So we can relieve mild or moderate second ray metatarsalgia only by first metatarsal lowering by scarf (2).
Fig. 36c2. Second ray pathology – Metatarsalgia: (2) elevation of the second metatarsal by BRT osteotomy.
1. When intermetatarsal angle is not large, we cannot lower the first metatarsal enough. In this case, if the second metatarsal is not too long, the BRT osteotomy (2) (3) is a good solution to relieve the second ray metatarsalgia.
Fig. 36c3. Second ray pathology – Metatarsalgia: (3) Weil osteotomy.
1, 2. When the second metatarsal is too long comparatively to the first one (dorso-plantar X-ray) and to the third one (medial oblique view), we have to perform a Weil osteotomy on the second metatarsal: Care has to be taken not to shorten too much. The third metatarsal has to remain shorter or equal to the second in the medial oblique view.
3. Single second metatarsal Weil osteotomy sometimes results in decreasing the second toe ground contact.
Postoperative training is very important to avoid this problem.
4, 5. Preferably, we perform Weil osteotomy also on the third and, if necessary, on the other lesser metatarsals.
MTP Dislocation
In our experience, the best results are observed by far with the shortening of the corresponding metatarsal by the Weil osteotomy. Emerging dis- location may be treated by a single Weil osteo- tomy, if the second metatarsal is too long. The best results are observed when the shortening of the metatarsal is generous – avoiding deformity, recurrence, stiffness or pain, so that single second ray osteotomy is rarely performed.
Generally the shortening concerns several lesser metatarsals, as far as the four last metatarsals. A more delicate problem is the correction of the MTP subluxation: The BRT osteotomy can pro- vide good results while additionally performing a Girdlerstone-Taylor l procedure. But in fact, in MTP dislocation, or even subluxation, which is in fact an early case of dislocation, the second metatarsal is usually too long, so that the Weil osteotomy is the most useful correction of this deformity.
Fig. 36d1. Second ray pathology – MTP dislocation: (1) The necessity of sufficient M2 shortening by Weil osteotomy.
In MTP second ray dislocation (1), insufficient M2 shortening may result in painful and stiff MTP joint (2) and remaining subdislocation (3); 4, 5. In this case, the M2 shortening is correct, but the excess of M3 length on the medial oblique view explains the transfer metatarsalgia.
Fig. 36d2. Second ray pathology – MTP dislocation: (2) The large shortening is effective.
1, 2. The large shortening is the best way to have a reliable correction of large or long-lasting MTP dislocation.
In these two cases, note the complete forefoot joint preservation (including the second toe).
Fig. 36d3. MTP Second ray pathology – MTP subluxation: Respective place of the BRT and the Weil osteotomies.
1, 2, 3. BRT osteotomy. The indication of this procedure is limited to emerging MTP subluxation clinically correctible, without too long second metatarsal. On this condition, the BRT osteotomy gives good results, combined to hammertoe correction.
4, 5. Weil osteotomy. When there is an emerging MTP dislocation (subdislocation, passively correctible on the foot examination), and when the second metatarsal is too long both in dorso-plantar and above all in the medial oblique view, we may perform Weil osteotomy just in the second metatarsal with a good result.
6, 7. The shortening has to be assessed on the medial oblique view: In this case, shortening of M2 is not sufficient: We also have to perform the shortening of the third metatarsal.
Anyway, isolated second ray pathology is exceptional: We have to take into account the disorders of the other rays.
Fig. 36e. Second ray isolated pathology?
1. In most cases the second ray pathology is certainly not isolated, but combined with first ray pathology.
2. We have to take care to the adjacent rays (a train may hide another one!) because of transfer metatarsalgia, particularly on the third ray (3). To avoid this, we can perform BRT osteotomy (4) or extend the Weil osteotomy on the third metatarsal (or even more) (5).
6. We also have to take care to the remaining plantar flexion of the third toe (one solution is the distal long flexor section).
7. Example of K-wiring with soft tissue procedure of not only the second but also the others lesser toes.
