Greater Tuberosity Osteotomy Research Articles

Additional cuff suture provides mechanical advantage for fixation of split-type greater tuberosity fracture of humerus

PurposeSplit type of greater tuberosity fracture has variety of surgical treatment options. This study aimed to compare the biomechanics property of additional cuff suture and other fracture fixation techniques. MethodsFifteen porcine humeri were categorized into three groups of fixation techniques those were proximal humeral internal locking system (PHILOS) plate with 2 cuff sutures, nonlocking (conventional, 3.5 mm) T-plate with 2 cuff sutures and T-plate with washer that had additional cuff suture (novel technique). Fracture was created by greater tuberosity osteotomy with 50˚ inclination to the line of surgical neck and then fixed with different prescribed techniques. Displacement of fracture site was measured with universal testing machine. The maximum forces to produce 3 mm, 5 mm of displacement and load to failure were recorded. ResultsThe average loads to reach 3 mm, 5 mm displacement and failure were 30.8 N, 45.4 N and 161 N for nonlocking T-plate; 76.6 N, 99.2 N and 144 N for PHILOS plate; 95.8 N, 120 N and 197 N for novel technique. The differences among three groups were significant in load to displacement at 3 and 5 mm (but not significant in load to failure). For load to reach 3- and 5-mm displacement, PHILOS plate and novel technique were significantly stronger than nonlocking T-plate (P < 0.05). For load to reach 3 and 5 mm displacement, novel technique was stronger than PHILOS plate but not significant (P > 0.05). For load to failure, novel technique was stronger than nonlocking plate and PHILOS plate but not significant (P < 0.05). ConclusionThe important factors affecting the strength of fracture fixation are type of plate and numbers of suture augmentation that tie to the plate. Fixation with additional cuff suture showed the superior biomechanics of load to reach 3 mm, 5 mm displacement with better load to failure compared with PHILOS plate and conventional T-plate alone.

Biomechanical evaluation of a new fixation technique for internal fixation of three-part proximal humerus fractures in a novel cadaveric model

Background The optimal surgical treatment for displaced proximal humeral fractures is still controversial. A new implant for the treatment of three-part fractures has been recently designed. It supplements the existing Expert Humeral Nail with a locking plate. We developed a novel humeral cadaveric model and the existing implant and the prototype were biomechanically compared to determine their ability in maintaining interfragmentary stability. Methods The bone mineral density of eight pairs of cadaveric humeri was assessed and a three-part proximal humeral fracture was simulated with a Greater Tuberosity osteotomy and a surgical neck wedge ostectomy. The specimens were randomly assigned to either treatment. A bone anchor simulated part of a rotator cuff tendon pulling on the Greater Tuberosity. Specimens were initially tested in axial compression and afterward with a compound cyclic load to failure. An optical 3D motion tracking system continuously monitored the relative interfragmentary movements. Findings The specimen stabilized with the prototype demonstrated higher stiffness ( P = 0.036) and better interfragmentary stability ( P values < 0.028) than the contralateral treated with the existing implant. There was no correlation between the bone mineral density and any of the investigated variables. Interpretation The convenience of this new IM-nail and locking plate assembly must be confirmed in vivo but the current study provides a biomechanical rationale for its use in the treatment of three-part proximal humeral fractures. The improved stability could be advantageous in particular when medial buttress is missing, even in osteoporotic bone.

Neer Award 2007: Reversion of structural muscle changes caused by chronic rotator cuff tears using continuous musculotendinous traction. An experimental study in sheep

Chronic rotator cuff tears are associated with irreversible architectural muscle changes and a high rate of repair failure. The changes observed in man and their irreversibility with a single stage repair can be reproduced in sheep. It was the purpose of this experiment to test the hypothesis that slow, continuous elongation of a retracted musculotendinous unit allows reversal of the currently irreversible structural muscle changes. The infraspinatus tendon of 12 sheep was released using a greater tuberosity osteotomy and allowed to retract for 4 months. Then, a new device was mounted on the scapular spine and used to extend the infraspinatus muscuculotendinous unit transcutaneously by 1 mm per day. Thereafter, the tendon was repaired back to the greater tuberosity. We assessed the muscular architecture using magnetic resonance imaging, macroscopic dissection, histology, and electron microscopy. Fatty infiltration (in Hounsfield units 1/4 HU) and muscular cross-sectional area (in % of the control side) were monitored with computed tomography at tendon release, initiation of elongation, repair, and at sacrifice. Sixteen weeks after tendon release, the mean tendon retraction was 29 +/- 6 mm (14% of original length, P = .008). In 8 sheep, elongation was achieved as planned (group I), but in 4, the elongation failed technically (group II). The mean traction time was 24 +/- 6 days with a mean traction distance of 19 +/- 4 mm. At sacrifice, the mean pennation angle in the infraspinatus of group I was not different from the control side (29.8 degrees +/-7.5 degrees vs. 30 degrees +/-6 degrees , P = .575). In group II, the pennation angle had increased from 30 degrees +/-6 degrees to 55 degrees +/-14 degrees (P = .035). There was no fatty infiltration at the time of tendon release. After retraction, there was a significant increase in fatty infiltration of the infraspinatus muscle and a decrease of its cross-sectional area to 57% of the contralateral side (P = .0001). During traction, the degree of fatty infiltration remained unchanged (36 HU to 38 HU, P = .381), and atrophy improved to a muscle square area of 78% of the contralateral side (P = .0001) in group I. In group II, an increase of fatty infiltration was measured from 36 HU to 28 HU; however, this increase was not significant (P = .144). Atrophy did not change in group II (57-55%, P = .946). At sacrifice, the remaining muscle mass was 64% in group I and 46% in group II (P = .019). Our preliminary results document, that continuous elongation of a retracted, fatty infiltrated and atrophied musculotendinous unit is technically feasible. In the sheep, continuous elongation can lead to restoration of normal muscle architecture, to partial reversal of muscle atrophy, and to arrest of the progression of fatty infiltration. Basic science level 2; Prospective comparative therapeutic study.

Proximal Humerus Fracture Sequelae

Our goal was to analyze the results of unconstrained shoulder replacement in a large series of sequelae of proximal humeral fractures in order to validate a previously described surgical classification. In a multicenter study, we retrospectively evaluated 203 patients with sequelae of proximal humeral fractures who were treated with a nonconstrained modular and adaptable prosthesis. The mean followup was 42 months (range, 24-96 months). We identified 137 impacted fractures with humeral head collapse or necrosis (Type 1 sequelae), 25 unreducible dislocations or fracture-dislocations (Type 2), 22 nonunions of the surgical neck (Type 3), and 19 severe tuberosity malunions (Type 4). Results of nonconstrained shoulder arthroplasty for the treatment of Type 1 and Type 2 sequelae were predictably good because no greater tuberosity osteotomy was performed. The distorted anatomy was accepted, and both the prosthesis and technique were modified accordingly. Total shoulder arthroplasty yielded better results than hemiarthroplasty. Patients with Type 3 or Type 4 sequelae had poor functional results with nonconstrained arthroplasty because greater tuberosity osteotomy was needed. This study validates our fracture sequelae classification. We no longer use unconstrained prostheses in Type 3 and Type 4 fracture sequelae and propose peg bone grafting or low-profile fracture prosthesis for patients with Type 3 sequelae and reverse arthroplasty for those with Type 4 sequelae. Prognostic study, level IV (case series). See Guidelines for Authors for a complete description of levels of evidence.

Shoulder arthroplasty for the treatment of the sequelae of fractures of the proximal humerus

The purpose of this multicenter study was to analyze the results of shoulder arthroplasty for the treatment of the sequelae of proximal humerus fractures and establish an updated classification system and treatment guidelines for these complex situations. Seventy-one sequelae of proximal humerus fractures were treated with shoulder replacement with the use of the same nonconstrained, modular, and adaptable prosthesis: the Aequalis prosthesis (Tornier Inc, St Ismier, France). The average time between initial fracture and shoulder arthroplasty was 5 years and 5 months. On the basis of anatomic classification schemes, sequelae were divided into 4 types: type 1, humeral head collapse or necrosis with minimal tuberosity malunion (40 cases); type 2, locked dislocations or fracture-dislocations (9 cases); type 3, nonunions of the surgical neck (6 cases); and type 4, severe malunions of the tuberosities (16 cases). The mean postoperative follow-up was 19 months (range, 12 to 48 months). Overall, the postoperative Constant score was excellent in 11 cases (16%), good in 19 cases (26%), fair in 18 cases (25%), and poor in 23 cases (33%). There were 18 complications (27%). Fifty-nine of 70 patients (81%) stated that they were satisfied with the result. The most significant factor affecting functional outcome was greater tuberosity osteotomy (P <.005). Regarding both surgical treatment and postoperative prognosis, we identify 2 categories of proximal humerus fracture sequelae: category 1, intracapsular/impacted fractures sequelae (associated with both cephalic collapse or necrosis [type 1] and chronic dislocation or fracture-dislocation [type 2]), in which an articulating joint can be reconstructed without a greater tuberosity osteotomy; and category 2, extracapsular/disimpacted fractures sequelae (associated with both surgical neck nonunions [type 3] and severe tuberosity malunions [type 4]) where the proximal humerus cannot be reconstructed without a greater tuberosity osteotomy. All of the excellent and good postoperative Constant scores were obtained in type 1 and 2, in which osteotomy of the greater tuberosity was not required. All patients in type 3 and 4, who underwent a greater tuberosity osteotomy, had either fair or poor results and did not regain active elevation above 90°. We conclude that a greater tuberosity osteotomy is the most likely reason for poor and unpredictable results after shoulder replacement arthroplasty for the treatment of the complex sequelae of proximal humerus fractures. Shoulder arthroplasty for the treatment of the sequelae of fractures of the proximal humerus should be performed without an osteotomy of the greater tuberosity when possible. If prosthetic replacement is possible without an osteotomy, surgeons should accept the distorted anatomy of the proximal humerus and adapt the prosthesis and their technique to the modified anatomy. A modular and adaptable prosthesis with both adjustable offsets and inclination may allow surgeons to adapt to a large number of malunions and may help to avoid the troublesome greater tuberosity osteotomy in a higher proportion of cases. (J Shoulder Elbow Surg 2001;10:299-308.)

Greater tuberosity osteotomy for treatment of impinge rotator cuff tear.

Forty-two consecutive patients in whom an impingement of rotator cuff tear had been treated with greater tuberosity osteotomy and repair were evaluated by relief of pain, return of range of motion and strength of shoulder. The oriental acromion is thin and easy to break during the traditional acromioplasty procedures. When the decompression is achieved by osteotomy on the greater tuberosity which is the common location of cuff tear, not only is adequate decompression achieved but also the coracoacromial ligament is preserved. Comparison of the results of greater tuberosity osteotomy with those of previous acromioplasty studies shows they are mostly similar. At present, these techniques can be recommended for use by Chinese orthopaedic surgeons who have to deal with the typical oriental bony structures.