Modified volar approach for proximal row carpectomy

Abstract

Objectives

Proximal row carpectomy is a well-accepted surgical procedure for the management of traumatic and degenerative wrist pathologies. It is routinely performed through a dorsal approach; a volar surgical access was presented in order to enable concomitant carpal tunnel release and avoid flexion limitation or disabilities caused by adhesions of the dorsal capsule and extensor tendons. We propose a modification to the volar approach, with detailed description of skin incision (reproducing the standard palmar access to the scaphoid), capsular section (beginning with a longitudinal cut radial to flexor carpi radialis tendon and prolonged transversally along the radio-lunate joint) and sequence of carpal bone removal (starting with the scaphoid rather than the lunate).

Materials and methods

The patients who underwent surgical treatment with modified volar proximal row carpectomy between 1992 and 2015 were enrolled in a retrospective analysis.

Results

We report postoperative improvement in both the Mayo Wrist score and total active range of motion in 38 patients, in line with the outcomes of dorsal proximal row carpectomy.

Conclusions

The modified volar approach is highly recommended when better visualization and access to proximal carpal bones are needed (particularly useful for inveterate perilunate dislocations), moreover if concomitant carpal tunnel syndrome or extensor tendon pathologies are present.

1. Introduction

Proximal row carpectomy (PRC) might be the recommended surgical technique for the management of several traumatic and degenerative conditions of the wrist, among which we include scaphoid lunate advanced collapse (SLAC), scaphoid nonunion advanced collapse (SNAC),¹ Kienböck disease,² irreducible or chronic perilunate dislocation, failure of previous surgeries³ and acute severe carpal trauma.⁴

Surgical techniques are commonly adopted according to arthritic stages, historically described by Watson⁵ and later modified.⁶ The management of stage II (radio-scaphoid ​± ​scapho-capitate osteoarthritis) or III (add luno-capitate osteoarthritis) is varied but the options with most reliable and predictable outcomes are PRC and 4-corner arthrodesis (4CA).^7,8

PRC is routinely performed through a dorsal incision (dPRC)⁹ however a volar approach (vPRC) was first conceived by Schernberg et al., in 1981,¹⁰ then by Bedeschi in 1990.¹¹ The aim of the palmar access is to enable concomitant carpal tunnel release and avoid potential flexion limitation or disabilities caused by adhesions of the dorsal capsule and extensor tendons.

To date only few studies^12,13 have described and reported results associated to vPRC. The aim of the palmar access is to enable concomitant carpal tunnel release and avoid potential flexion limitation or disabilities caused by adhesions of the dorsal capsule and extensor tendons.

The technique detailed in this paper adopts a volar approach but differs from the previous ones in both skin/capsular incision and sequence of carpal bone removal.

The aim of this study is to describe the volar approach for PRC and to investigate its long-term functional and clinical results in terms of AROM (active range of motion) and Mayo Wrist Score.¹⁴

2. Materials and methods

All the patients who underwent surgical treatment with modified vPRC technique in our Department between 1992 and 2015 were enrolled in a single-center retrospective analysis.

Exclusion criteria were: subjects who were treated with different techniques (dPRC or standard vPRC), soft tissue interposition, capitate resurfacing or interventions carried out before 1992 or after 2015. Seventy-four patients were enrolled. Patient demographic information and PRC indications are resumed in Table 1.

Table 1.

Study population age and sex distribution and volar proximal row carpectomy indications. Scaphoid Lunate Advanced Collapse (SLAC), Scaphoid Nonunion Advanced Collapse (SNAC).

Age	Mean 47 years (26–70)
Sex	Male n ​= ​49 (66,2 ​%)	Female n ​= ​25 (33,8 ​%)
Indication for vPRC	Kienböck disease (n ​= ​21–28,4 ​%)	SLAC (n ​= ​19–25,7 ​%)	SNAC (n ​= ​16–21,6 ​%)	chronic carpal dislocation (n ​= ​13–17,6 ​%)	radio-carpal arthritis (n ​= ​5–6,7 ​%)

All the operations, in the entirety of the surgical procedures, were performed by three expert surgeons, according to levels of expertise rating criteria.¹⁵ Wirist radiographs were taken at three, six, 12 months postoperatively. Afterwards radiographs were taken at final follow-up. Thirty-eight patients underwent clinical and radiological examination at an average time of 11 years (range 5–21 years) after surgery while 36 subjects (49 ​%) were lost at follow-up.

Ethical approval

All procedures performed were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Ethical approval declaration not required. All patients enrolled signed informed consent.

2.1. Surgical technique

The modified vPRC is performed under regional anaesthesia. The upper extremity is placed on an arm table with the shoulder abducted and fully externally rotated, elbow slightly flexed and forearm in maximal supination.

The skin incision, initially reproducing the standard volar approach to the scaphoid, begins with a hockey-stick made over the distal flexor carpi radialis (FCR) tendon, angled radially and distally towards the thenar eminence to avoid inadvertent injury of the palmar branch of the median nerve and exposing the scapho-trapezial joint. Hence, it is ulnarly prolonged following the distal flexion crease to half of the wrist (Fig. 1A). The antebrachial fascia is divided in line with its fibres, just radially to the FCR tendon which is retracted in an ulnar direction to expose the volar capsule. The palmar branch of the radial artery is identified and protected throughout the surgical procedure. The volar capsule is sectioned longitudinally and flaps are raised ulnarly and radially. Once the volar approach to the scaphoid is performed, the bone is dissected by severing both the radio-scaphoid (RS) and radioscaphocapitate (RSC) ligamentous attachments (Fig. 1B) and afterwards removed en block (Fig. 1C). Thereafter, the transverse carpal ligament is exposed and opened along its ulnar aspect. The median nerve is identified and isolated then it is ulnarly retracted together with the flexor digitorum superficialis, profundus and palmaris longus tendons to expose the volar capsule, that is sectioned transversally along the radio-lunate joint (Fig. 2A). The lunate is thus removed, taking care not to damage the head of the capitate and the lunate fossa of the radius (Fig. 2B). Eventually, the median nerve and the flexor tendons are retracted radially and the volar capsule transversal cut is prolonged ulnarly for about 1 ​cm to expose and harvest the triquetrum (Fig. 3A).

Fig. 1.

Skin incision (A); scaphoid dissected from both capsular and ligamentous attachments (B); scaphoid removed en block (C).

Fig. 2.

The median nerve, the flexor digitorum superficialis and profundus, the palmaris longus tendons are retracted ulnarly to expose the radio-lunate joint (A); lunate removed en block (B).

Fig. 3.

Triquetrum removed en block (A); the volar capsule is sutured back to normal (B).

The RS and RSC ligaments are not repaired but the two palmar capsular incisions (transverse and longitudinal) are carefully and tightly sutured (Fig. 3, Fig. 4). (The capsular portion of RS and RSC ligaments are partially sutured during capsular closure).

Fig. 4.

The palmar capsule is sectioned along the radio-lunate joint (A); suture of the transversal incision (B); suture of the longitudinal incision (C); suture of the antebrachial fascia (D); image summarizing volar capsular incisions (and sutures) with radioscaphocapitate ligament left unrepaired (E).

At last, the skin is closed (Fig. 5A), a suction drain is set up and the wrist is immobilized in a removable volar splint with 35° of extension (Fig. 5B) for four weeks. Digital motion is encouraged. After seven days, the rehabilitation program is started under hand therapists’ supervision, including passive stretching but also active assisted flexion-extension mobilization to preserve wrist range of motion. By four to five weeks, a strengthening program is started based on isometric and progressive resistant exercises. The rehabilitation protocol lasts six weeks, after which light manual tasks are allowed; full return to heavy manual work is usually possible after three/four months.

Fig. 5.

The skin is sutured; scaphoid, lunate and triquetrum are removed en block (A); suction drain is seat and the wrist is immobilized in a removable volar splint (B).

2.2. Clinical evaluation

At an average of 132 months (11 years) after surgery (range 5–21 years), the patients were recalled to carry out a clinical examination, evaluated using the modified Mayo Wrist Score¹⁴ plus active range of motion (AROM). Complications as infection, instability or ulnar translation of the carpus were recorded. The modified Mayo Wrist Score includes both patient and physician participation to assess pain, the active flexion/extension arc (in comparison with the contralateral side), grip strength (in comparison with the contralateral side), and the ability to return to regular employment or activities (patient's satisfaction). This system includes two categories of subjective data (pain and satisfaction), and two categories of objective data (active range of motion and grip power) to calculate scores (0–25) and then total sum of scores is evaluated for 4 results categories, such as excellent (91–100), good (80–90), fair (65–79) and poor (less than 65).¹⁶

3. Results

The average modified Mayo Wrist Score increased from 43 to 75 ​at final follow-up. Regarding the pain domain of the Mayo Wrist Score most subjects (34, 89 ​%) reported no pain, whilst mild-occasional and severe-persistent pain was observed in three and one cases respectively. The mean active range of motion (AROM) flexion/extension increased from 69.4° (35.0° flexion and 33.9° extension) preoperatively to 84.5° (44.5° flexion and 40.0° extension) postoperatively. The AROM of the radio-ulnar deviation increased from 22.6° (7.0° radial deviation and 15.6° ulnar deviation) pre-operatively to 35.2° (8.5° radial deviation and 26.5° ulnar deviation) postoperatively (Fig. 6). No cases of ulnar translocation of the carpus, infection and carpus instability were observed (Fig. 7). Two patients underwent wrist arthrodesis respectively six and eight years after vPRC (5.3 ​%).

Fig. 6.

Flexion, extension, radial and ulnar deviation, Total Active Motion (TAM) at last follow-up.

Fig. 7.

Active post-operative range of motion at 8-year follow-up (A–B); excellent aesthetic outcome (C); coronal and sagittal CT views of the radio-capitate articulation at 8-year follow-up (D).

4. Discussion

We report an improvement in both the Mayo Wrist score and total active range of motion, (Mayo Wrist Score increased from 43 preoperatively to 75 ​at final follow-up). The vPRC ensures an optimal exposure of proximal carpal bones, reducing the risk of damaging the cartilage of the proximal pole of the capitate or the lunate fossa of the distal radius.

The clinical and functional results obtained at a mean follow-up of 11 years suggest modified vPRC provides long-term improvement in both Mayo Wrist Score and total AROM. Similar results were reported by Van Amerongen and Schuurman¹²; they registered improvement in DASH score, preserved motion and grip strength after vPRC, with no ulnar translocation of the carpus. Our results are comparable to those reported in literature for dPRC.17, 18, 19, 20 Bjon et al.²¹ reported after a mean follow-up of 97.9 months a mean Mayo Wrist Score of 69, AROM in flexion/extension of 93° and 28° AROM of the radio-ulnar deviation for PRC performed through dorsal approach. Regarding AROM our outcomes are in contrast with the results of Luchetti et al. that report a decreased wrist extension at an average of 20 months follow-up, following the standard vPRC.¹³ In our series the need of conversion to wrist arthrodesis is 5.3 ​%, in line with literature results.^22,23

We routinely perform modified vPRC, leaving RC and RSC ligaments unrepaired, but we have never observed ulnar translocation of the carpus. The absence of this fearsome complication in our series might be due to the opposing action of radial capsule and dorsal radiotriquetral ligament (also known as dorsal radio-carpal ligament) that are always left intact. Since we do not routinely register ulnar translocation, we prefer to continue leaving the RSC ligaments unrepaired, even if different RCS ligament reconstruction techniques have been described in literature24, 25, 26 with good results.

PRC is a universally recognized procedure for the treatment of numerous traumatic and degenerative wrist pathologies and is usually performed through a dorsal approach.^27,28

The volar approach was first conceived to enable concomitant carpal tunnel release but also to avoid flexion limitation or disabilities caused by adhesions of the dorsal capsule and extensor tendons, which are possible complications related to the dorsal incision.¹³

The main changes to the standard volar approach include: 1) skin incision (which enables better visualization and access to proximal carpal bones); 2) capsular section beginning with a longitudinal incision just radial to FCR tendon and prolonged transversally along the radio-lunate joint (which reduces the risk of capsular retraction and adhesion with the classical inverted T incision); 3) sequence of carpal bone removal, beginning with the scaphoid instead of the lunate (which makes easy to harvest the lunate and lowers the chance to damage the cartilage of the capitate head or lunate fossa).

The major complications following vPRC are represented by progressive radiocapitate arthritis and ulnar translocation of the carpus. Appropriate patient selection is therefore fundamental,^29,30 considering this technique in specifically selected cases: subjects older than 35 years of age and involved in less demanding activities, no rheumatologic copathologies, no osteoarthritis of the proximal pole of the capitate and lunate fossa.

The main limitations of this study include its single-centre design, the high number of losses to follow-up, the use of Mayo Wrist Score as single functional outcome and absence of a control group. The results should therefore be confirmed by future studies with higher methodological standards, comparing the modified vPRC with the standard vPRC and the dPRC in a prospective trial.

5. Conclusions

The modified volar approach is highly recommended when better visualization and access to proximal carpal bones are needed (particularly useful for inveterate perilunate dislocations), moreover if concomitant carpal tunnel syndrome or extensor tendon pathologies are present.

Disclosure of interest

Conflict of Interest: none declared.