Proximal Row Carpectomy Using Decellularized Dermal Allograft: Preliminary Results

Abstract

Objective  The purpose of this study was to evaluate the short-term outcomes of patients undergoing proximal row carpectomy (PRC) with interposition arthroplasty using a decellularized dermal allograft.

Methods  Patients with a minimum of 1-year follow-up after undergoing a PRC using decellularized dermal allograft were contacted for clinical evaluation, radiographs, and postoperative outcome questionnaires, including the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire as well as the modified Likert scale for patient satisfaction. Nine of ten (90%) consecutive patients who were treated using this surgical technique were available for follow-up.

Results  At a mean follow-up of 18 months, a total of nine patients achieved a mean flexion-extension arc of 113 degrees, pronosupination of 170.5 degrees, grip strength of 68 Ibs and pinch strength of 17 Ibs. Relative to the contralateral side, these values were 95, 100, 84 and 82%, respectively. There was significant improvement in the mean DASH score from 63.5 preoperatively to 23.8 postoperatively. Patient satisfaction postoperatively achieved a mean modified Likert score of 1.5. There was no evidence of radiocarpal joint space degeneration or dislocation in any of the patients. No patient suffered wound-related issues, foreign-body reaction to the graft, or other complications.

Conclusion  PRC with interposition arthroplasty using a decellularized dermal allograft in patients with degenerative changes at the lunate fossa or capitate demonstrates short-term outcomes comparable to what has been reported for routine PRC in patients without degenerative changes affecting the radiocapitate joint. This method of interposition arthroplasty expands the indications for PRC and may help avoid salvage, motion-sacrificing procedures in select patients with late-stage wrist arthritis.

Level of Evidence  This is a level IV, therapeutic study.

Since its first description by Stamm, ¹ proximal row carpectomy (PRC) has shown to be a valuable surgical option for the treatment of wrist arthritis. It has shown to be an effective treatment for arthropathy secondary to scapholunate advanced collapse, scaphoid nonunion advanced collapse, Keinböck's disease, and the sequelae of perilunate dislocations. ^{2 3} Long-term pain relief with acceptable levels of wrist range-of-motion (ROM) and strength has been shown in most patients with up to 20-year follow-up. ⁴ The decision to perform a PRC depends largely on patient-specific factors and the degree of wrist arthritis. PRC has often been compared to partial wrist arthrodesis with scaphoid excision and four-corner fusion, since the indications are similar and long-term outcomes are satisfactory. Often times, patient factors such as younger age and occupation (i.e., manual labor) push the favorability toward partial wrist arthrodesis as it has been shown to better preserve wrist strength than PRC. ^{5 6 7} When motion-sparing options and other treatments have failed, salvage surgery in the form of total wrist fusion is available as a last resort.

One of the major limitations and contraindications for PRC is degenerative changes at the lunate fossa or capitate. In this setting and in patients with physically demanding manual occupations, partial wrist arthrodesis is indicated. Select patients who fall into this category, however, may not be ideal candidates for partial wrist arthrodesis; these include individuals at higher risk for nonunion or those unable to tolerate an extended period of immobilization. In these patients or among those in whom wrist ROM is a priority or those who failed a partial wrist arthrodesis, PRC may be preferred. The presence of mild degeneration of the capitate has not precluded good to excellent results of PRC and thus, the acceptable degree of capitate or lunate facet degeneration to achieve satisfactory results with PRC has not been clearly established. The shortcomings of standard PRC to treat patients with these contraindications have sparked innovation for interposition arthroplasty. Many modifications of standard PRC have been described and include dorsal capsular interposition flaps, ^{8 9} osteochondral resurfacing of the arthritic capitate, ^{10 11} partial capitate resection, ¹² meniscal allograft interposition, ¹³ pyrocarbon implants, ¹⁴ and hemiarthroplasty. ¹⁵ PRC with interposition arthroplasty may also prove to be advantageous in improving the durability of the radiocapitate (RC) articulation. Progressive RC degeneration in patients who have previously undergone standard PRC is a concern and has been seen in patients with longer follow-up. ⁴ Although the radiographic changes have not been proven to correlate with wrist pain and function, collapse of the joint space has been shown in patients who failed standard PRC and subsequently underwent salvage total wrist fusion. ⁴

The aim of this study is to evaluate the short-term radiographic and clinical results of our previously described technique of PRC with interposition arthroplasty using decellularized dermal allograft. ¹⁶ We hypothesized that our clinical results among patients with degenerative changes at the capitate or lunate fossa will compare favorably to those reported for routine PRC in patients without capitate or lunate fossa arthritis.

Materials and Methods

Between January 2015 and March 2018, 10 consecutive patients with radiocarpal arthritis presented to our institution and underwent PRC with interposition arthroplasty using decellularized dermal allograft. These patients were identified by searching our electronic database for Current Procedural Terminology (American Medical Association, Chicago, IL) code 25215 (carpectomy; all bones of proximal row) and then looking through the operative reports to determine if an additional interpositional arthroplasty was performed. Inclusion criteria were patients who had at least 1-year follow-up after undergoing an isolated PRC with decellularized dermal allograft for radiocarpal arthritis (without radiographic evidence of radiolunate or capitolunate degeneration) and intraoperative evidence of capitate or lunate facet degeneration. Patients who underwent this procedure for failed partial wrist arthrodesis were included as well. All procedures were performed by a single surgeon using our previously described surgical technique and postoperative protocol. ¹⁶ After a standard dorsal approach to the wrist joint and carpectomy of the proximal row, the volar wrist capsule is tagged with heavy nonabsorbable suture in a figure-of-eight fashion. Double-loaded 3.5-mm suture anchors are placed into the radial aspect of the hamate and the nonarticular portion of the capitate. The decellularized dermal allograft is first sized by folding it onto itself so that a square piece, about twice the size of the capitate head articular surface, is cut out. The measured graft is then sutured together with heavy, nonabsorbable suture in a simple, running, and locking fashion, as shown in Fig. 1A . Sutures from the anchors are passed through the corners of the graft while the volar capsule suture is passed through the central portion of the graft. The graft is then pulled down, draping over the capitate head. The passed sutures are then tied so that the graft is secured to the capitate, hamate, and volar capsule. Another heavy, nonabsorbable suture is passed through the dorsal capsule and graft and tied so that the capsule covers the graft as well. The wrist is then ranged to confirm adequate range of motion. Fig. 1B displays the complete PRC with interpositional decellularized dermal allograft, folded onto itself and sewn together. Fig. 2 illustrates the steps involved in preparing the graft.

Fig. 1.

( A ) Clinical photo of a prepared piece of decellularized dermal allograft. The graft had been folded over onto itself and secured with a running, locking nonabsorbable suture. ( B ) Intraoperative photo of the new radiocapitate articulation interposed with decellularized dermal allograft, doubled up onto itself and fixed to the capitate and hamate (with suture anchors) as well as the volar and dorsal capsule.

Fig. 2.

Illustration depicting the steps involved for graft preparation. ( A ) The graft is first folded in half and placed into the radiocapitate space. ( B ) It is then sized and cut to snuggly fit in the new articulation. The dimensions of the graft are usually approximately 35 mm × 25 mm × 7 mm. ( C ) The folded and cut graft is then secured together using a heavy, nonabsorbable suture that is ran in a simple, locking fashion. ( D ) Suture from the volar capsule stitch is then passed through the central portion of the graft, as marked by the red line closest to the left. ( E ) The graft is then secured to the capitate and hamate anchors by passing the sutures from the anchors through the corners of the graft (marked by the red lines at the corners). After the graft is placed into the new joint space and snuggly draped over the capitate, another heavy, nonabsorbable suture is passed through the dorsal capsule and graft and tied so that the capsule securely lies over the graft (red line closest to the right and centrally within the graft). Image courtesy: Rabinovich and Lee. ¹⁶

Patients were recalled for clinical and radiographic evaluation at 3, 6, and 12 months followed by yearly follow-up after 12 months. At final follow-up, clinical evaluation consisted of wrist ROM (flexion, extension, pronation, and supination) using a goniometer as well as grip and pinch strengths using a Jamar Hand Dynamometer and Pinch Gauge (Sammons Preston, Inc., Bolingbrook, IL). Measurements were obtained for both wrists and hands for comparison. The Disabilities of the Arm, Shoulder, and Hand (DASH) and modified Likert questionnaires were obtained either during the clinical visit or over the telephone. The modified Likert questionnaire used was a 5-point grading scale rating the patient's level of satisfaction after the procedure. Grade 1 indicated the highest level of patient satisfaction whereas grade 5 denoted the lowest level of patient satisfaction, where the patient noted, in hindsight, that they would not undergo the procedure again. Grade 2 indicated the patient was satisfied with the procedure; grade 3 indicated the patient was neither satisfied nor dissatisfied with the procedure and for grade 4 the patient was somewhat dissatisfied with the procedure. Posteroanterior (PA) and lateral radiographs of the patients' affected wrist were obtained and evaluated for preservation of the RC joint space and the presence of any adjacent degenerative changes. RC height was measured on PA radiographs as the distance from the center of the articular portion of the capitate to the lunate facet of the distal radius. This measurement was obtained (in millimeters) at the initial postoperative visit (RC ₁ ) and at final follow-up (RC ₂ ). The clinical and radiographic evaluations were performed by either the attending surgeon or chief orthopaedic resident. Statistical analysis was done using Microsoft Excel 2008 for MAC (Redmond, WA) and included means, ranges, and standard deviation. Paired t -test was used for comparison of pre and postoperative DASH scores.

Results

Upon retrospective chart review, 10 patients who met our inclusion criteria were identified. Of the 10 patients who met inclusion criteria, one patient was lost to follow-up before 1 year. This was due to the patient moving away from the state and simply not returning to the office for their scheduled appointment. This left nine patients with complete follow-up data. The demographic information is summarized in Table 1 . There were seven males and two females with an average age of 66 years (range 54–74) at the time of surgery. The injury involved the dominant hand in four of the nine cases. Postoperative clinical outcomes are summarized in Table 2 . Mean follow-up after surgery was 18 months (range 12–36). The mean wrist ROM was a flexion-extension arc of 113 degrees (range, 90–130 degrees), and a pronation-supination arc of 170.5 degrees. The mean postoperative grip and pinch strength was 68 Ibs (range, 30–110 Ibs) and 17 Ibs (range, 6–27 Ibs), this being 84 and 83% relative to the contralateral side, respectively. The mean pre- and postoperative DASH scores were 63.5 and 23.8. This difference was statistically significant at p  < 0.05. None of the patients demonstrated translation or subluxation of the wrist joint on PA and lateral wrist radiographs at final follow-up. Radiographic review also did not show any collapse of the radiocarpal space and no adjacent degenerative bony changes were appreciated. The mean radiocarpal space on PA radiographs was 3.94 and 2.52 mm on the first postoperative and most recent postoperative films, respectively. Fig. 3A through D shows radiographs of patient 6, depicting adequate maintenance of the RC articulation after 15 months follow-up. No postoperative complications were noted upon chart review or at the time of last in-person follow-up, including wound issues/infection, foreign body reaction to the allograft, or neurovascular injury.

Table 1. Patient demographics.

Patient	Gender	Age a	Dominant wrist	Underlying etiology	Final follow-up b
1	Male	65	Not affected	SL ligament injury	36
2	Female	72	Affected	Distal radius fracture malunion	32
3	Male	59	Affected	Nonunion of scaphoid excision, 4-corner fusion	16
4	Female	70	Not affected	SL ligament injury	16
5	Male	68	Not affected	SL ligament injury	12
6	Male	62	Affected	SL ligament injury	15
7	Male	72	Not affected	Distal radius fracture malunion	12
8	Male	74	Not affected	Lunate AVN	12
9	Male	54	Affected	SL ligament injury	12

Abbreviations: AVN, avascular necrosis; SL, scapholunate.

^aAge measured in years.

^bFinal follow-up measured in months.

Table 2. Post-op clinical outcomes.

Patient	Wrist FE (degrees)	Wrist PS (degrees)	Grip strength (Ibs)	Pinch strength (Ibs)	Pre-op DASH	Post-op DASH	Modified Likert	RC 1 (mm)	RC 2 (mm)
1 a	130 degrees (113%)	170 degrees (100%)	70 (108%)	18 (100%)	46.6	0	1	2.12	1.97
2	115 degrees (85%)	180 degrees (100%)	35 (70%)	14 (88%)	94.8	22.5	1	2.42	1.74
3	105 degrees (95%)	165 degrees (100%)	85 (71%)	16 (70%)	40.8	14.2	2	4.34	4
4	105 degrees (91%)	170 degrees (100%)	45 (100%)	20 (87%)	82.4	21.4	1	4.87	1.8
5	125 degrees (100%)	170 degrees (100%)	60 (80%)	13 (48%)	46.4	32.5	1	3.77	2.9
6	112 degrees (86%)	180 degrees (100%)	100 (100%)	23 (100%)	65.5	39.6	2	3.16	2.16
7	115 degrees (92%)	170 degrees (100%)	80 (80%)	20 (100%)	74.1	7.1	1	6.40	2.51
8 b	120 degrees (105%)	170 degrees (100%)	30 (50%)	6 (55%)	60.2	69.4	4	3.29	1.47
9	90 degrees (75%)	160 degrees (100%)	110 (96%)	27 (93%)	60.8	7.5	1	5.10	4.07

Abbreviations: DASH, Disabilities of the Arm, Shoulder; FE, flexion-extension arc; PS, pronation-supination arc; RC _1, radiocapitate width (in millimeters) upon initial post-op visit; RC _2, radiocapitate width (in millimeters) upon most recent post-op visit.

Note: Wrist range-of-motion was measured using a goniometer in degrees. The values in parentheses are percentages relative to the contralateral uninjured side. Grip and pinch strength are reported in pounds (Ibs), the values in parentheses are a percentage of the contralateral uninjured side.

^aPatient had a standard PRC performed on the contralateral side.

^bPatient has a history of stroke, polio, and peripheral neuropathy affecting his operative extremity more than his contralateral side.

Fig. 3.

( A ) PA and ( B ) lateral radiographs of the operative wrist of patient 6 upon their initial postoperative visit. There is maintenance of the radiocapitate space, a width of 3.16 mm, when measured between the center of the capitate and the lunate fossa. ( C ) PA and ( D ) lateral radiographs obtained 15 months later, demonstrating continued maintenance of the radiocapitate articulation (with a space of 2.15 mm) without evidence of degenerative changes or subluxation. PA, posteroanterior.

Discussion

PRC is an accepted surgical option for the treatment of symptomatic and functionally limiting wrist arthritis. A relative contraindication to this procedure is the presence of any degeneration at the capitate base or lunate fossa of the distal radius, although this has been questioned. The severity of capitate or lunate fossa arthritis to favor a partial wrist arthrodesis is not well defined and many attempts to address these degenerative changes without proceeding to fusion have been attempted with satisfactory results. Gaspar and colleagues ⁸ recently compared patients to radiocarpal arthritis and involvement of the capitate/lunate fossa who underwent PRC with dorsal capsule interposition arthroplasty to a group of patients without such involvement who underwent standard PRC. Both groups had significant improvements in mean grip strength, ROM, and outcome scores without a difference in results for any of the outcomes, suggesting the benefit of dorsal interposition PRC in patients with degenerative changes at the capitate base and lunate fossa. Kwon et al similarly performed a PRC with a dorsal capsular interposition flap in patients with wrist arthritis affecting the capitate and lunate fossa and achieved significant improvements in pain and function while maintaining preoperative ROM and grip strength. ⁹ Osteochondral resurfacing of the capitate with PRC has also been described, ¹⁰ demonstrating significantly improved postoperative pain levels and modified Mayo wrist scores with preservation of mean wrist ROM and grip strength. Longer-term follow-up (mean 101 months) of this procedure has been reported, noting comparable outcomes to standard PRC in patients without capitate chondrosis on patient-directed outcomes tools (DASH and Mayo Wrist Score). ¹¹ Interposition arthroplasty using fascia lata allograft has also been used for radioscaphoid arthritis after resecting affected portions of the scaphoid and distal radius. ¹⁷ Among 20 patients with close to a mean 4-year follow-up, improvements in wrist ROM, grip strength, and pain were exhibited. All patients returned to their preoperative occupations. Results using a resurfacing capitate pyocarbon implant with PRC have also shown improved pain and outcome scores with preservation of motion and strength in the setting of advanced wrist arthritis. ¹⁸ These results compared favorably to a comparison group of patients who underwent PRC alone for arthritis limited to the radioscaphoid joint, further supporting the widened indication for PRC when incorporating an interposition arthroplasty.

Following standard PRC, the biomechanics of the wrist joint are markedly altered due to mismatch between the proximal capitate radius of curvature and the radius of curvature of proximal lunate. Imbriglia et al ¹⁹ pointed out that due to these differences in radii of curvature between the capitate and lunate facet, there is resultant rotational and translational motion at this new interface. This also leads to incongruent stresses at the new articulation with contact area and peak pressure in the lunate fossa increasing substantially, independent of wrist position. ²⁰ Additionally, the central area of bony contact is shifted 5.5 mm radially; dorsal and volar translation occurs with wrist flexion and extension and there is distribution of pressure over a greater area. The placement of an interposition arthroplasty may help re-create near anatomical radiocarpal pressures and contact areas, a goal our technique aims to achieve. This has been demonstrated in a cadaveric model using an interposition lateral meniscal allograft. ²¹

Our preliminary results of PRC with decellularized dermal allograft among patients with radiocarpal arthritis and capitate and/or lunate fossa involvement compare favorably to the results reported in the literature for standard PRC among those with less advanced arthritis. The mean wrist flexion-extension arc among patients in our series is 113 degrees, which is 93% of the contralateral wrist, while grip and pinch strengths are 84 and 83% relative to the contralateral side. These results are similar, if not better, than what has been reported in the literature for standard PRC, which is average wrist ROM between 61 and 78% and average grip strength between 78 and 92% of the contralateral side, respectively. ^{2 4 22} The mean RC space at latest follow-up (ranging between 1 and 3 years) was 2.52 mm and no evidence of degeneration was apparent in any of the patients. This compares favorably to the mean RC space reported after standard PRC. ^{6 22} Of note, we did not double-up the graft in our initial two patients using this technique and only began to fold the graft over onto itself starting with the third patient in our series. A concern with any form of interposition arthroplasty that does not utilize autograft is foreign body reaction, especially with hardware or allograft tissue. No patients in our series demonstrated signs of this reaction or graft rejection, which can present subtly with persistent postoperative pain. Namdari and colleagues ²³ reported two cases of foreign body giant cell reaction requiring revision surgery in their series of 11 patients that underwent biologic glenoid resurfacing with an acellular, matrix-based scaffold. Savoie et al ²⁴ noted a similar allergic reaction when attempting to augment rotator cuff repairs using a patch made of porcine small intestine submucosa cells. The true incidence of foreign body reaction to decellularized dermal grafts is unknown. Suspicion should be raised in any patient undergoing a procedure using this graft material who continues to have postoperative pain not attributable to another cause.

A major utility of our technique is expanding PRC to patients with more advanced arthritis who would otherwise be indicated for arthrodesis. Arthrodesis surgery is technically more demanding than PRC, involves a longer recovery period of immobilization and is fraught with complications such as nonunion and donor site morbidity when harvesting autograft. As mentioned previously, certain patients such as those at risk for nonunion and those who would be noncompliant with an extended recovery or simply yearn for a quicker return to their routine lifestyle/occupation may be better suited with a PRC interposition arthroplasty. The disadvantages of standard PRC, such as loss of carpal height, formation of an incongruous joint, and potential for progressive degenerative arthritis of the RC space may be better addressed with an interposition arthroplasty, especially with a strong, robust buffer such as a dermal allograft. Our technique may also be advantageous in the revision setting. One patient in our series (patient 3 in Tables 1 and 2 ) developed a nonunion after scaphoid excision, four-corner fusion. Instead of attempting revision open reduction, takedown of the nonunion and re-attempt at fusion, the patient opted for PRC with decellularized dermal allograft and has maintained satisfactory results at 16 months postoperatively.

Several limitations are present in this study beginning with the intrinsic biases of its retrospective design. Although the goal of this study is to present the early, preliminary outcomes of patients undergoing this technique, a larger pool of patients in addition to a control group would have been more informative. Longer than minimum 1-year follow-up would also serve to be very useful in assessing the longevity of our technique and any specific delayed or late-stage complications that may be encountered. In our series of patients, objective preoperative pain, ROM, and strength values were not recorded. This information would have been helpful for comparison to postoperative values to better assess the degree of clinical improvement. One of the strengths of this study is performance of PRC with decellularized dermal allograft by a single surgeon, eliminating the technical confounders brought on with multiple surgeons. Further study and area of research entails a larger sample size with longer follow-up and comparison to patients undergoing standard PRC.

Funding Statement

Funding None.