Humpback Deformity Research Articles

Retrospective Review of 234 Scaphoid Fractures and Nonunions Treated with Arthroscopy for Union and Complications

The purpose of this paper is to retrospectively review 234 consecutive cases of scaphoid fractures and nonunions treated using arthroscopy with the dorsal percutaneous implantation of a headless compression screw for healing and complications. Solid union of fracture is determined by CT scan. We identified 126 acute injuries, including 65 proximal pole fractures; 67 grossly displaced fractures; 12 trans-scaphoid perilunate dislocations including four trans-scaphoid trans-capitate fractures; and ten combined scaphoid and distal radius fractures. 108 scaphoid nonunions were identified. 98 were correctly aligned and ten had a humpback deformity which was correctable using arthroscopic assisted reduction techniques at the time of surgery. 82 presented with a fracture gap 2mm or greater requiring percutaneous bone grafting. 12 cases of avascular necrosis (AVN) were identified by MRI. 20 nonunions had surgery performed at other institutions. The mean time to surgery for the nonunions was 20 months. 99% union rate of acute scaphoid fractures was obtained by 12 weeks, as determined by CT scan. Two complications were identified (3%). One case of delayed healing was identified. this delayed union was treated with percutaneous bone grafting and continued on to heal uneventfully. The other complication was a case of volar trans-scaphoid peri-lunate dislocation. While the fracture healed, the patient developed a traumatic dislocation requiring a capitate-lunate arthrodesis. Treatment of scaphoid nonunions resulted in ten cases of delayed healing, which were treated with repeat percutaneous bone grafting. This represented a 9% complication rate. of the ten cases of delayed unions that were re-bone grafted, four failed to heal by nine months. This resulted in a 96% union rate of our nonunion group by nine months. when acute fracture healing was compared to nonunions the average healing of acute fractures as determined by CT scanning measuring trabecular bridging was 12 weeks, while the average healing of non-unions was 22 weeks. We conclude that the dorsal percutaneous treatment of scaphoid fractures and nonunions using arthroscopy is safe and effective. CT scans to evaluate scaphoid healing by measuring trabecular bridging at the fracture site was determined to be an excellent modality to evaluate scaphoid healing. While not witnessed in this series, the potential for complications requires proper training.

Volar Wedge Grafting for Scaphoid Nonunion With Collapse

Fractures of the scaphoid waist that fail to heal tend to collapse into a flexed posture. The so-called "humpback deformity" of the bone is accompanied by collapse of the proximal carpal row with dorsal tilt of the lunate. It is possible to restore scaphoid height and carpal alignment by insertion of a tricortical wedge of graft from the iliac crest. In this article, we demonstrate the surgical technique of volar wedge grafting for scaphoid nonunion.

Technique for Percutaneous Fixation of Displaced and Nondisplaced Acute Scaphoid Fractures and Select Nonunions

Percutaneous surgical intervention for scaphoid fractures and some nonunions is increasingly common. There is a considerable learning curve for these procedures. Here we review basic and advanced techniques for volar and dorsal fixation of acute nondisplaced and displaced fractures as well as nonunions with minimal resorption and no humpback deformity.

Free Medial Femoral Condyle Bone Grafting for Scaphoid Nonunions With Humpback Deformity and Proximal Pole Avascular Necrosis

Treatment of scaphoid nonunions remains a challenging problem, especially in the setting of proximal pole avascular necrosis or humpback deformity. Conventional bone grafting techniques have demonstrated unpredictable results in the setting of collapse deformities, whereas pedicled dorsal distal radius vascularized bone grafts have recently been reported to have nearly a 50% failure rate when used in scaphoid nonunions with proximal pole nonunion. Free vascularized medial femoral condyle bone grafting is one option for the treatment of scaphoid nonunions with proximal pole avascular necrosis associated with a humpback deformity. The indications, contraindications, and technique of free vascularized medial femoral condyle bone grafting are presented for the treatment of scaphoid nonunions associated with proximal pole avascular necrosis and humpback deformities.

Scaphoid Nonunion Treated With Vascular Bone Grafts Pedicled on the Dorsal Supra-retinacular Artery of the Distal Radius

Nonunion and avascular necrosis (AVN) are frequent complications of scaphoid fractures. We describe the operative technique and long-term results of treatment with pedicle vascularized bone grafts (VBGs) of the distal radius in patients with scaphoid fractures in whom nonunion and AVN developed. During a 4-year period (1997-2000), VBGs pedicled on either the first and second or second and third compartments of the supraretinacular artery of the distal radius were in our hospital used to treat 11 patients with symptomatic scaphoid nonunion involving AVN of the proximal fragment (one with perilunate transscaphoid fracture dislocation and 10 with displaced scaphoid fractures with nonunion). Nine of these 11 patients received fixation with divergent K-wires fixation and two received Herbert screws fixation. Osseous union was achieved in all 11 patients treated with VBGs within an average period of 13 weeks. Functional results of treatment, which were measured using the modified Mayo Wrist Score, were encouraging in all patients in this series (four excellent, six good, and one fair). The deformity of ununited scaphoid was well corrected. The index study suggests that this treatment can be used not only to revascularize necrotic scaphoid, but also to correct humpback deformity and the resulting carpal instability.

Vascularized Bone Grafts From the Palmar Radius for the Treatment of Waist Nonunions of the Scaphoid

With their intrinsic vascularity vascularized bone grafts provide an alternative solution to the challenging problem of scaphoid nonunions. The union rate (after imaging evaluation including magnetic resonance imaging [MRI]) and functional outcome of using vascularized bone grafts pedicled on the palmar carpal epiphyseal artery for waist nonunions of the scaphoid are reported in this prospective case series. The technique was applied to 9 waist nonunions resulting from fractures. The mean time elapsed from the initial injury to the procedure was 22 months and the mean follow-up time was 24 months. The graft was pedicled on the artery running at the distal edge of the pronator quadratus and was inserted in the nonunion as an intercalary graft. Six patients had postoperative MRIs to evaluate fracture healing and graft incorporation. Union was accomplished in all cases between 6 and 12 weeks. Postoperative MRI showed the viability of the graft (contrast-enhanced images) and confirmed union and graft incorporation. Complete absence of pain was noted in all patients. The Mayo modified wrist score increased from 63 to 92 after surgery and according to this score results were excellent in 5 patients and good in 4. Vascularized bone grafts from the anterior radius lead to rapid union and consolidation in cases of waist nonunion. Postoperative MRI confirms viability of the graft, union, and graft incorporation. The approach is limited to the distal radius and wrist and lacks donor site morbidity. The interposition of the graft from the palmar side allows correction of the humpback deformity and patients regain carpal height, grip strength, and painless motion. Therapeutic, Level IV.

The Outcomes and Complications of 1,2-Intercompartmental Supraretinacular Artery Pedicled Vascularized Bone Grafting of Scaphoid Nonunions

Over the past decade vascularized bone grafts that use a 1,2-intercompartmental supraretinacular artery (1,2-ICSRA) pedicle have gained popularity in the treatment of scaphoid nonunions. The purpose of this study was to evaluate critically the outcome, complications, and failures of 1,2-ICSRA-based vascularized bone grafting at our institution to understand better the appropriate indications, methods, and possible contraindications. From January 1994 through July 2003, 50 scaphoid nonunions in 49 patients were treated with 1,2-ICSRA-based vascularized bone grafts. A retrospective review of the clinical and radiographic information was performed. Two patients were lost to follow-up study. Nine female and 38 male patients averaging 24 years of age were followed-up for an average of 7.8 months. Thirty-four scaphoid nonunions went on to union at an average of 15.6 weeks after surgery. Complications occurred in 8 patients and consisted of graft extrusion, superficial infection, deep infection, and failure of fixation. Univariate risk factors for failure included older age, proximal pole avascular necrosis, preoperative humpback deformity, nonscrew fixation, tobacco use, and female gender. Although previous researchers have concluded that vascularized bone grafts based on the 1,2-ICSRA are efficacious in the treatment of scaphoid nonunions, we determined that a successful outcome is not universal and depends on careful patient and fracture selection and appropriate surgical techniques. Therapeutic, Level IV.

Corrective osteotomy for symptomatic scaphoid malunion

A prospective study aimed at assessment of the outcome of management of symptomatic scaphoid malunion (hump-back deformity). The work included 13 scaphoid malunions in 13 patients. All patients complained of weak painful hand grip and limitation of wrist function. All cases were subjected to a corrective opening wedge scaphoid osteotomy with insertion of a trapezoid-shaped tricortical iliac bone graft. At the final assessment, after a mean follow-up period of 42 months, the achieved results were rated excellent in seven cases, good in four and fair in two according to the scoring system used. Objectively, the mean range of wrist motion and hand grip strength improved from 48% and 47% pre-operatively to 82% and 79% at the final assessment. Radiological parameters including height to length ratio, lateral intrascaphoid angle and dorsal cortical angle were also effectively improved. The intra-operative corrected carpal alignment has almost been maintained at the final follow-up. The procedure did not have serious drawbacks such as non-union or avascular necrosis and perhaps might delay the development of degenerative arthritis of the wrist.

Technique: vascularized bone grafts from the volar distal radius to treat scaphoid nonunion

The use of vascularized bone grafts to treat scaphoid nonunion has been proposed by various investigators. We examined the blood supply to the palmar surface of the distal radius in 40 fresh cadavers that were injected with a colored latex solution and determined that the radial portion of the palmar carpal arterial arch can serve as a pedicle for vascularized grafts. Scaphoid nonunions with a humpback deformity can be corrected by harvesting a wedge of vascularized bone from the palmar cortex of the distal radius, providing easier access to the scaphoid deformity compared with the use of dorsal distal radius vascularized grafts. We also review our series of 72 patients treated by this technique.

Management of Scaphoid Nonunions

Scaphoid nonunions result in a predictable pattern of wrist arthrosis. To minimize the incidence of arthrosis, the goal of treatment should be consolidation of the fracture with the scaphoid in anatomic alignment. Computed tomography and magnetic resonance imaging scans can aid evaluation of carpal collapse, scaphoid collapse, scaphoid nonunion, bone loss, and detection of osteonecrosis. Nonunion of the scaphoid waist may result in a humpback deformity, increasing the chances of further collapse and arthrosis. This collapse deformity must be approached volarly with an intercalary bone graft and internal fixation. A dorsal approach to proximal scaphoid nonunions allows easier access for removing the necrotic bone from the proximal pole and applying accurate screw or pin fixation. Vascularized bone graft is recommended to manage scaphoid nonunions with osteonecrosis.

Scaphoid nonunion: correction of deformity with bone graft and internal fixation

The scaphoid is the most commonly fractured bone in the carpus. Although greater than 90% of scaphoid fractures unite with cast immobilization, failure to heal remains a clinical reality, particularly when the fracture is displaced or associated with intracarpal instability [1–3]. Dabezies [4] reported a 55% incidence of nonunion and a 50% rate of proximal pole avascular necrosis (AVN) in scaphoid fractures with greater than 1 mm of displacement. Cooney and colleagues [2] noted a nonunion rate of 46% for 13 displaced scaphoid fractures. Scaphoid nonunion has been associated with progressive symptomatic radiocarpal and midcarpal arthrosis [5–7]. This arthrosis is the sequela of altered wrist kinematics [3,8,9]. The alteration of wrist kinematics reflects not only motion through the nonunion site, but also the apex-dorsal malalignment of the scaphoid (the so-called humpback deformity) with associated dorsal angulation of the lunate and alteration in carpal height [10,11]. Although scaphoid deformity and its adverse effects on kinematics were recognized early on by Fisk [12], for many years the standard treatment of symptomatic scaphoid nonunion was based on gaining union without an attempt to correct the deformity of the scaphoid. It has been recognized, however, that some patients with residual bony deformity of the healed scaphoid may continue to have pain and functional limitations [13–15]. As a result of a greater appreciation of carpal kinematics, many authors now believe that the approach to a scaphoid nonunion should consist of realigning the scaphoid anatomy and gaining union. Scaphoid deformity Posttraumatic scaphoid deformity is complex but predictable. Displaced scaphoid fragments lie in a so-called humpback configuration with flexion of the distal fragment. The dorsal intercalary pattern of carpal instability (DISI) follows [16]. With the use of three-dimensional reconstructions of computed tomography images, the three-dimensional orientation of a fractured scaphoid has been represented more clearly. Belsole and coworkers [17] looked at a series of scaphoid nonunions and performed a detailed three-dimensional CT evaluation comparing the fractured and contralateral scaphoids. They found that the proximal scaphoid fracture component is extended, radially deviated, and supinated in relation to the distal fracture component. They also identified that the volume and configuration of missing bone is consistent. The amount of the scaphoid bone that was lost varied from 6% to 15% of bone volume. The bony defect is prismatic with a quadrilateral base facing palmarly.

Use of the 1,2 intercompartmental supraretinacular artery as a vascularized pedicle bone graft for difficult scaphoid nonunion.

Fourteen patients with established scaphoid nonunion were treated with vascularized pedicle bone grafting. All nonunions healed at a mean of 11.1 weeks (range, 8-16 weeks). Wrist motion was minimally affected by surgery. Intercarpal and scaphoid angles were improved after surgery, particularly in patients with preoperative humpback deformity who had previous interposition grafting. Outcome, based on a self-assessment questionnaire administered at a mean 30 months of follow-up (range, 19-53 months), showed 2 excellent, 7 good, 4 fair, and 1 poor result. Three patients showed progressive radioscaphoid arthrosis. Vascularized bone grafts are indicated in proximal pole fracture nonunions, in the presence of avascular necrosis, and after conventional grafts. Radiocarpal arthritis, if present before surgery, is a poor prognostic sign.

SCAPHOID NONUNIONS

Our ability to treat scaphoid nonunions has improved dramatically. The degree of collapse and bone loss can be accurately assessed in waist fractures using sagittal images on CT scans. These nonunions require reduction and bone grafting to re-establish the normal geometry of the scaphoid. Magnetic resonance imaging helps evaluate whether or not avascular necrosis is present in the proximal pole. Because of the poor prognosis of conventional bone grafts, a vascularized bone graft is recommended as the primary treatment when AVN is present. The volar collapse of the humpback deformity is best corrected with a volar approach and the proximal pole nonunion is best approached using a dorsal approach. Nearly all proximal pole nonunions require a vascularized bone graft and all acute proximal pole fractures require open reduction and internal fixation. Using specially designed cannulated screws, the nonunions can be stabilized accurately to decrease the time to resolution of the nonunion and minimize the amount of time in a cast. Stable fixation requires that the screw fixation target the central portion of the scaphoid regardless of the type of screw design used. Using these techniques, the hand surgeon should be able to provide a reasonable prognosis for patients presenting with a scaphoid nonunion, and the treatment should result in functional range of motion, grip strength, and relief of pain.

Management of proximal scaphoid bone pseudarthroses and fractures with the mini-Herbert screw via a dorsal approach

32 patients, aged 16 to 49 years, were treated by osteosynthesis using the Herbert mini screw. The indications were five fractures (type B3, Herbert classification), two delayed unions (type C) and 25 nonunions (type D1 to D3, Filan and Herbert classification). Six patients received no bone grafts, 19 received cancellous bone graft from the radius. An interpositional iliac crest bone graft was used in four, and a vascularized bone graft from the distal radius in three cases respectively. The average postoperative immobilisation in a forearm splint was nine weeks. 26 patients could be recruited for clinical follow-up at an average of 14.5 months. The radiological results were assessed in 30 cases (94%). Bony consolidation was achieved in 26 cases (100% of the fractures, 84% of the nonunions). In three cases a loosening of the screw, and in three further cases a dislocation into the radiocarpal joint were observed. A humpback deformity was present in four cases. Three patients showed a persisting nonunion, one patient a fibrous union. Early degenerative changes of the radiocarpal joint were observed in six cases. The clinical follow up examination showed an average grip strength of 91% (JAMAR II), 94% for the three finger, and 95% for the pinch grip compared to the contralateral side. The mean postoperative pain score on the visual analog scale was one for resting conditions, eleven for motion and 33 under stress. The range of motion was 79% of the opposite side for extension/flexion and 83% for radial/ulnar deviation. The average DASH-score reached 15 points. The Herbert mini screw has proven to be a reliable implant for reconstruction of proximal pole fractures and nonunions of the scaphoid.

Osteosynthesis of carpal scaphoid nonunion with interpositional bone graft and Kirschner wires: a 3- to 6-year follow-up.

Malreduced or neglected unstable carpal scaphoid fractures may lead to nonunion, which is often difficult to treat and carries the risk of carpal instability and degenerative arthrosis. Here, we describe a new "sandwich" method, which takes advantage of minimal dissection and has promising results. From 1989 through 1992, we treated 39 patients with scaphoid nonunion by using the sandwich method that consisted of a wedge corticocancellous strut graft and numerous cancellous bone chips. Divergent Kirschner wires were used for fixation of reduction. We retrospectively review 26 scaphoids with follow-up periods of 3 to 6 years. The functional outcome was evaluated with modification of the Mayo Wrist Scoring Chart. The radiographs were analyzed, and tomographs were used for confirmation of osseous union. All 26 scaphoids united within 4 months. The carpal instability and humpback deformity were corrected. In all cases, the functional results were either good or excellent. Interpositional bone grafts corrected scaphoid angulation and length. Divergent multiple pinning rather than screws avoids unwanted shearing and rotational force during application and provides stable fixation with minimal dissection. Most of scaphoid nonunions in our series were the oblique type in which the lag screw never created perfect compression because of a shearing force.

Clinical Utilisation of Computed Tomography of the Scaphoid.

Computed tomography is the best imaging modality to assess bony architecture. Scanning in the longitudinal plane of the scaphoid provides a greater appreciation of the humpback deformity. CT scan provides superior assessment of union and has a higher correlation with operative findings. A limitation of CT scanning is partial volume averaging which may give a false impression of a partial union when a nonunion exists. Height-to-length ratio provides superior observer variability for the assesssment of the humpback deformity. CT is useful to be able to "template" the proposed surgery of the scaphoid. It allows the surgeon to determine whether a structural bone graft is required, the preferred screw fixation and whether a volar or dorsal approach is required.

Measurement of the scaphoid humpback deformity using longitudinal computed tomography: Intra- and interobserver variability using various measurement techniques

The intra- and interobserver variability of 3 techniques for measuring the humpback deformity of 37 scaphoids using longitudinal computed tomography was assessed. The 3 measuring techniques were the lateral intrascaphoid angle, the dorsal cortical angle, and the height-to-length ratio. The intraobserver reliability of the intrascaphoid angle was poor; the dorsal cortical angle was moderate to excellent, and the height-to-length ratio was excellent. The interobserver reliability of the intrascaphoid angle was poor to moderate, the dorsal cortical angle was moderate to excellent, and the height-to-length ratio was moderate to excellent. For all 3 observers, the intra- and interobserver reliability was the best for the height-to-length ratio and worst for the intrascaphoid angle. The height-to-length ratio is the most reproducible method of assessing the humpback deformity. Clinical correlation is required to establish whether the height-to-length ratio will be of value in predicting the outcome of fractures of the scaphoid.

Subacute Scaphoid Fractures

Twenty-three subacute scaphoid fractures were retrospectively reviewed to determine the efficacy of nonoperative treatment. All of the patients sought medical attention between 4 weeks and 6 months after injury, and their fractures were classified according to location and stability. Nineteen fractures were observed to radiographic union or until closed treatment was abandoned; four patients were lost to followup. Nine of 10 stable subacute middle-third scaphoid fractures healed with cast immobilization in an average of 19 weeks (range, 11 to 38), and these were compared with a randomly selected group of acute middle-third fractures that healed in an average of 10 weeks (range, 6 to 13). Five of six unstable subacute middle-third fractures healed in an average of 20 weeks. One of these had a symptomatic humpback deformity treated by cheilectomy. Of three subacute proximal-third fractures, only one healed after 29 weeks of closed treatment. This study demonstrates that stable subacute middle-third scaphoid fractures will heal with cast treatment but may take twice as long to do so as stable acute middle-third fractures. Unstable subacute middle-third scaphoid fractures and subacute proximal-third fractures appear less likely to heal with closed treatment.

Biomechanical changes of the wrist flexor and extensor tendons following loss of scaphoid integrity.

Loss of integrity of the scaphoid may change the motion center of the entire carpus, and deformities from scaphoid fractures may alter the location of motor tendons of the wrist, thus altering their biomechanics. The goal of this study was to clarify biomechanical changes in these tendons following loss of scaphoid integrity. Excursions and moment arms of the principal flexor and extensor tendons of the wrist were investigated in seven cadaveric upper extremities in intact wrists after simulation of scaphoid waist fracture and after removal of the proximal scaphoid. Excursions of the flexor carpi radialis and ulnaris, extensor carpi radialis longus and brevis, and extensor carpi ulnaris tendons were measured with rotary potentiometers during wrist flexion-extension and radioulnar deviation. Simultaneously, wrist joint angulation was recorded. Moment arms of the tendons were derived from tendon excursions and joint motion. After scaphoid fracture, the moment arms of the flexor carpi radialis and extensor carpi ulnaris tendons increased significantly during wrist flexion-extension, whereas the moment arms of the extensor carpi radialis longus and brevis tendons decreased significantly. After proximal scaphoid excision, the moment arms of the extensor carpi radialis longus and brevis tendons again decreased significantly during wrist flexion-extension. The moment arms of the flexor carpi radialis and extensor carpi radialis brevis tendons increased significantly during radioulnar deviation, whereas those of the wrist motors on the ulnar side decreased. These findings indicate the importance of the integrity of the scaphoid in maintaining normal biomechanics of motor tendons of the wrist. An increase in the moment arm of the radial wrist flexor along with a decrease in moment arms of the radial extensors constitutes as etiology for persistent angulation of the scaphoid and the humpback deformity. In addition, disturbing the biomechanics of the wrist motor tendons predisposes the carpal joints to abnormal loading, potentially contributing to the development of carpal joint degeneration.

A Case of familial hyperparathyroidism presenting with hypercalcemic crisis

Familial isolated hyperparathyroidism (FIHP), a specific type of primary hyperparathyroidism, is known to be asymptomatic despite the accompanying dangerously high levels of calcium and advanced bone or renal disease. In this report, we describe the case of a 47 year-old female with familial hyperparathyroidism, being presented in hypercalcemic crisis with severe bone lesions. She complained of the classic symptoms of hyper-calcemia, such as anorexia, thirst, palpitation and muscle weakness. A physical examination revealed a hump-back deformity associated with a severe thoracic scoliosis and a large neck tumor at the upper pole of the left thyroid lobe. Her serum calcium concentration was 19 mg/dl, her alkaline phosphatase concentration was 2,691 IU/L, and her intact PTH was 3,830 pg/ml. A skeletal survery of the whole body showed the severe osteolytic changes of hyperparathyroidism. Cervical exploration was undertaken, and a tumor (6cm in diameter) was removed. Histological examination revealed a parathyroid chief cell adenoma. In review of this case along with previously reported cases of FIHP in Japan, all cases of hypercalcemia with a calcium concentration greater than 14 mg/dl had exhibited typical hypercalcemic symptoms. Also, many of the urolithiasis-negative cases had significant bone symptoms and signs associated with hyperparathyroidism. Age at diagnosis as hyperparathyroidism is higher in bone-type cases than in urolithiasis-positive cases. The reason for these results is probably due to a lack of urolithiasis that may show early signs of hypercalcemic disorder. In conclusion, it is suggested that hypercalcemic and bone symptoms associated with hyperparathyroidism are not rare in patients with FIHP in Japan, and early recognition of hyperparathyroidism in the family member through long-term follow-up is necessary to avoid a life threatening hypercalcemic crisis as in the present case.