Arthroscopic assessment of avascular necrosis

Avascular necrosis of the lunate is a process that is not well understood. The cause is uncertain, but a common theory persists that it is caused by disruption of the vascular supply to the lunate. This article discusses an approach to assessment that respects the articular cartilage and places at the front of the decision-making process the pathoanatomic components of the articular cartilage. It primarily respects the articular cartilage in the patient with avascular necrosis. This approach was developed for avascular necrosis of the lunate, but in principle applies to other joints with avascular necrosis as well.     

Coexisting avascular necrosis of the scaphoid and lunate

Reports of coexisting avascular necrosis of more than one carpal bone are rare. We report coexisting avascular necrosis of the scaphoid and lunate in a 56-year-old woman with no history of using steroids or injury. We treated her with a radioscapholunate fusion with two angled 2.4 mm distal radius plates to stabilise the locking plate. At her 12-month follow up there was no evidence of non-union.     

Coexisting avascular necrosis of the scaphoid and lunate

Abstract

Reports of coexisting avascular necrosis of more than one carpal bone are rare. We report coexisting avascular necrosis of the scaphoid and lunate in a 56-year-old woman with no history of using steroids or injury. We treated her with a radioscapholunate fusion with two angled 2.4 mm distal radius plates to stabilise the locking plate. At her 12-month follow up there was no evidence of non-union.     

腕月骨无菌性坏死的病因学研究

目的：探讨月骨无菌性坏死的病因。方法：通过对腕关节机能解剖、月骨内微组织结构及腕关节X线影像学的研究，阐明月骨无菌性坏死的致病因素。结果（1）月骨的血运有20％由掌侧或背侧单一滋养血管供血或主要供血，这类单侧主干型血供的月骨易发生无菌性坏死。（2）月骨内骨小梁的走行方向由远端行向近端，相互平行，这与月骨的应力传导方向相一致。（3）月骨内微血管中央段的数量多而小，掌侧段血管稍粗大，血管面积及其与骨截面积比值最大。（4）病变组月骨呈掌屈畸形。结论：月骨无菌性坏死的病因是月骨内外多种因素作用的结果。     

Transient vascular compromise of the lunate after fracture-dislocation or dislocation of the carpus

Although classic avascular necrosis of the lunate is rare after fracture-dislocation or dislocation of the carpus, these severe carpal injuries can compromise the vascular supply of the lunate. The lunate thus develops a relative increase in radiodensity. Our finding of an incidence of 12.5%--three of 24 cases--suggests a relatively frequent occurrence. The clinical course was transient with resolution of abnormal radiodensity and subjective findings. Moreover, none of the three cases progressed to classic avascular necrosis of the lunate, Kienb?ck's disease. The clinician should not confuse this transient vascular compromise of the lunate with Kienb?ck's disease, but should be aware of the entity and its benign, self-limited course and should treat it expectantly.     

Coexisting Kienböck's and Preiser's Disease of the Wrist: Experience with Proximal Row Carpectomy with Dorsal Capsular Interposition Technique

Background

Idiopathic avascular necrosis of the lunate is known as Kienböck's disease and that of the scaphoid is known as Preiser's disease. Because the prevalence of coexisting Kienböck's and Preiser's diseases is very low, standardized stages of disease and treatments are not established.

Case Presentation

We report coexisting avascular necrosis of the scaphoid and lunate in a 68-year-old woman with no history of steroids or other risk factors. We treated her with proximal row carpectomy with capsular interposition technique. A distal-based dorsal capsular flap was prepared and repaired the palmar capsule. At the last follow-up, she had no pain and had gained improved range of wrist motion. There was no arthritic change at the newly formed radiocapitate joint.

Conclusions

In the case of collapsed lunate and scaphoid with avascular necrosis, the proximal row carpectomy procedure has an advantage. Proximal row carpectomy with dorsal capsular interposition can be performed when the lunate or scaphoid cannot be saved. Arthritic changes of the capitate head and distal radius lunate facet can be covered with the dorsal capsule.     

头状骨移位替代坏死月骨的解剖研究及其临床应用

目的　介绍一种治疗晚期月骨无菌性坏死的新术式。方法　对 5 0侧上肢标本进行显微解剖并观测腕部的血管结构。对 10 0侧腕骨标本中头状骨与月骨进行对比观测 ,并做相关性分析。设计以骨间前动脉背侧支为蒂的头状骨移位术 ,替代坏死碎裂的月骨。临床应用 2 0例 ,术后随访 1～ 13年。结果　头状骨与月骨的几何形状、外径和关节面的弧高、弧长极其相似 ,相关性显著。移位的头状骨有可靠的血运。 2 0例头状骨移位替代坏死月骨者术后腕痛消失 ,保持了腕高、腕骨间的稳定和腕关节的功能。结论　该术式符合腕关节的功能解剖和力学传导 ,是治疗晚期月骨无菌性坏死的较好方法。     

Palmar-divergent dislocation of the scaphoid and the lunate

We describe a patient with palmar-divergent dislocation of the scaphoid and lunate. After successful closed reduction, the scapholunate and lunotriquetral ligaments were sutured through the dorsal approach, and the anterior capsule was sutured through the palmar approach. The scapholunate and lunotriquetral joints were fixed with Kirschner wires for 7 weeks. At the 1-year follow-up, magnetic resonance imaging showed no evidence of avascular necrosis of the scaphoid or lunate, and radiographs showed no evidence of the dorsal and volar intercalated segment instability patterns associated with carpal instability. However, flexion of the scaphoid and a break in Gilula’s line remained. To our knowledge, this is the first report showing treatment of palmar-divergent dislocation of the scaphoid and lunate by suturing the carpal interosseous ligaments.     

100?Jahre nach Kienb?ck

Kienb?ck's disease (KD) leads to collapse of the lunate bone with severe consequences for the wrist function which for some patients may result in occupational invalidity. The many synonyms of KD (aseptic necrosis or avascular necrosis) insinuate that the true etiopathology remains poorly understood. This reviews aims at exploring the level of evidence which brought forward the different hypotheses on the origin of KD. The widespread theories about the origin were formed about 100 years ago but a specific therapy is still not within reach. Although the cause of the disease remains essentially unknown it is officially recognized as an occupational disease in Germany. Empirical attempts to explain the etiopathology are based on compression of the lunate, impaired vascularity through vibration exposition, fracture and dislocation of the lunate from the radiolunate fossa. The level of evidence urges a cautious interpretation of currently discussed hypotheses on the etiology of KD.     

Microsurgical reconstruction of the scaphoid and lunate bones with small, free vascularized iliac crest bone grafts

The primary surgical goal in repairing a scaphoid nonunion, particularly one associated with avascular fragments, or reconstructing the lunate is to prevent progressive carpal collapse. In patients with persistent nonunion of the scaphoid and progressive aseptic necrosis of the lunate bone, reconstruction can be managed with a small microvascular iliac crest bone transfer. This retrospective study reports on the anatomical fundamentals, the operative procedure (particularly the harvesting of the bone flap and microsurgery), the assessment of the viability of the bone graft and the postoperative results in 80 out of a total of 210 patients on whom the surgery had been performed. From 1985 until 1998, 210 carpal bone reconstructions (134 scaphoid bones and 76 lunate bones) were performed using small, free vascularized iliac crest bone grafts. Of these, 80 patients were preoperatively evaluated and postoperatively followed up clinically and by means of conventional radiography and magnetic resonance imaging (MRI). The total rate of viability and bony union was 91.2%. This means a bone flap loss-rate and, consequently, a progressive arthrosis/necrosis/persistent nonunion of 8.8%. The patients who had vital reconstructed carpal bones did not report pain, but motion and grip strength were decreased as compared with the uninvolved side. This procedure offers stability and vascularity to treat avascular scaphoid nonunion and has proved beneficial in achieving union in avascular scaphoid pseudoarthrosis and lunate necrosis. It can be considered to be the definitive alternative technique. The high rate of union and the absence of progressive carpal arthrosis are the best evidence for the vascularity of the bone graft.     

Total volar extrusion of the lunate and scaphoid proximal pole with concurrent scapholunate dissociation

This article describes a case of a 24-year-old man with a total volar extrusion of the lunate and scaphoid proximal pole with concurrent scapholunate dissociation. The viability of the lunate and the proximal pole of the scaphoid are at high risk in this type of injury. Scaphoid nonunion, avascular necrosis of the lunate and proximal pole of the scaphoid, and carpal instability are inevitable unless the blood supply is restored. Thus, proximal row carpectomy at injury may be an acceptable option to avoid these complications and late sequelae, including chronic wrist pain and dysfunction. However, the authors attempted accurate reduction of the extruded bones and internal fixation.Final radiographs and magnetic resonance imaging 12 years postoperatively showed healing without avascular necrosis. Carpal indices involving the scapholunate angle, radiolunate angle, and carpal height ratio were similar in both wrists without evidence of carpal instability or collapse. Range of motion and grip power were 75% and 76%, respectively, compared with those of the uninjured wrist. Clinical scores showed good results, and the patient reported no pain during activities of daily living and was satisfied with his surgical results. Open reduction and internal fixation can be a viable option in this rare pattern of injury.     

Oblique shear fractures of the lunate

Traumatic fractures of the lunate are rare. This article presents two patients who had displaced oblique lunate fractures and distal radius fractures. Both fractures achieved union; however, transient avascular necrosis occurred in the proximal healing of one patient.     

Kienböck's disease in a 12-year-old girl

A case of avascular necrosis of the lunate in a 12-year-old girl is described. Conservative treatment resulted in a clinically normal wrist at three years' follow-up, despite obvious radiological changes.     

Late treatment of a dorsal transscaphoid, transtriquetral perilunate wrist dislocation with avascular changes of the lunate

The outcome of delayed treatment of an unreduced transscaphoid, transtriquetral, perilunate fracture dislocation of the carpus is unpredictable. Long-term follow-up observations in a 22-year-old man treated three months postinjury showed changes in the lunate consistent with avascular necrosis at the time of open reduction and internal fixation. Early resolution of this was evident by nine months, and complete resolution was seen at the follow-up examination (four years and two months). Despite delay in treatment, this patient had full, pain-free wrist motion. Consequently, avascular changes of the carpus following wrist dislocation do not preclude a good result. Anatomic reduction of the scaphoid, as well as the midcarpal joint, and restoration of the articular surface of the lunate, are most important in determining prognosis.     

Arthroscopic assessment and classification of Kienbock's disease

The authors have utilised arthroscopy to assess and classify Kienbock's avascular necrosis of the lunate. The classification is based on the number of articular surfaces of the lunate and adjacent articulation, which are non-functional. Kienbock's disease usually affects the proximal surface of the lunate first with subsequent secondary changes to the lunate facet of the radius. Advanced cases and those with a coronal fracture of the lunate will cause involvement of the mid carpal joint. Surgery is aimed to debride the joint, classify the level of disease and direct the definitive procedure to be performed. If the articular surfaces are intact, a synovectomy or radial shortening would be indicated. If there is involvement of the lunate but an intact lunate facet a proximal row carpectomy would be indicated. If there is involvement of the proximal lunate and lunate facet then a radio-scapholunate fusion could be utilised. More extensive involvement of the joint would require a wrist fusion. Arthroscopy provides a valuable assessment and subsequent classification of Kienbock's disease.     

The role of imaging in the assessment of vascularity at hand and wrist

The viability of the bone is compromised in two main situations at the wrist: Kienb?ck's disease and scaphoid nonunion with avascular necrosis. Plain radiography and CT allow an accurate anatomical approach of morphological changes associated with avascular necrosis of the lunate and the scaphoid fracture with complications. CT is readily available to detect nondisplaced fractures. However, early forms of necrosis can be misdiagnosed and evaluation of bone vitality is impossible. MRI is the best imaging modality to detect avascular necrosis and the intravenous injection of gadolinium improves the specificity of diagnosis of necrosis. The lack of enhancement of the proximal fragment of the scaphoid leads the surgeon to use a vascular graft in the treatment of nonunion. The technique has its limitations. The bone necrosis is histologically complex and contrast enhancement does not mean necessarily viability. However, MRI is still the most powerful imaging modality in the assessment of the bone marrow.     

Double bundle tendon graft for rotational stabilization of lunate implant arthroplasty

Kienbock's disease can lead to unsalvageable collapse of the lunate due to avascular necrosis but with reasonably intact cartilage surfaces preserved at the head of the capitate and lunate fossa of the radius. An emerging alternative to traditional treatments for this stage is lunate implant arthroplasty with a hard material. Although, the problem of osteolysis previously seen with silicone implant arthroplasty is expected to be overcome, stabilization of both the implant and the carpus as a whole remains a challenge. The described surgical technique uses a double bundle tendon graft to stabilize the lunate implant against both excessive translational as well as sagittal plane rotational motions. The strategy also stabilizes the scaphoid and the carpus against intercalated segment instability and collapse.     

The Proposal and Early Results of Capitate Forage as a New Treatment Method for Kienböck's Disease

Kienböck's disease is a type of avascular necrosis which disrupts the biomechanics of the wrist as a result of the changes it creates in the lunate bone. Its treatment generally consists of osteotomies intended to relieve the pressure on the bone, pedicle bone grafting applications aiming to increase bone blood supply, and salvage procedures. Capitate forage is a safe and simple-to-apply surgical treatment method which is intended to enhance neovascularization of the lunate much like a radius osteotomy or core decompression     

Apport de l’imagerie dans le diagnostic de la vascularisation osseuse à la main et au poignet

The viability of the bone is compromised in two main situations at the wrist: Kienböck's disease and scaphoid nonunion with avascular necrosis. Plain radiography and CT allow an accurate anatomical approach of morphological changes associated with avascular necrosis of the lunate and the scaphoid fracture with complications. CT is readily available to detect nondisplaced fractures. However, early forms of necrosis can be misdiagnosed and evaluation of bone vitality is impossible. MRI is the best imaging modality to detect avascular necrosis and the intravenous injection of gadolinium improves the specificity of diagnosis of necrosis. The lack of enhancement of the proximal fragment of the scaphoid leads the surgeon to use a vascular graft in the treatment of nonunion. The technique has its limitations. The bone necrosis is histologically complex and contrast enhancement does not mean necessarily viability. However, MRI is still the most powerful imaging modality in the assessment of the bone marrow.     

Vascularised bone graft and osteotomy of the radius in Kienböck's disease

Treatment of stage IIIA and III B avascular necrosis of the lunate bone remains controversial. We present a series of 5 cases in young patients treated with a vascularised bone graft from the second metacarpal, combined with a lateral shortening and closing wedge osteotomy of the radius. Good clinical and radiographic results were obtained and disease progression was halted with the combination of these two surgical procedures.