The treatment of geriatric proximal humerus fracture has evolved a lot in the modern era. Factors such as patient’s age, severity of the fracture and presence of glenohumeral dislocation [9], all play a role in surgeon’s decision. Geriatric fractures are considerably more challenging to treat surgically given the high prevalence of osteoporosis and poor rotator cuff status. As the fracture pattern becomes more complex and displaced, the less clear the optimal treatment is. The overall trend is moving towards operative treatment [8], with plate fixation, hemiarthroplasty and reverse total shoulder arthroplasty all being reasonable options, albeit each has its own benefits and specific risks.
The invention of locking compression plate (LCP) revolutionized the surgical technique of fracture fixation. The concepts of MIPO, preservation of blood supply and locking head screws [33] are ideal for fixation of osteoporotic bone, with promising clinical results [34] in most fractures. Despite LCP can exhibit a greater holding force of the humeral head than conventional plates [35], it is not without risks. Hardeman et al [36] evaluated 307 shoulders with an overall 15.3% failure rate and 23.8% re-operation rate at 4.3 years. The most common reported complications include screw penetration, loss of reduction and avascular necrosis [37,38]. Screw penetration more often than not require a revision procedure, either in the form of removal of implants or conversion to some form of shoulder arthroplasty. Loss of reduction primarily occurs in the presence of varus malreduction [12]. Predictors include Neer 3-part or 4-part fractures [38], older age, osteoporosis, initial varus displacement, medial comminution, inadequate reduction and insufficient medial support [39]. Intra-operative anatomical reduction and restoration of medial cortical support are essential for successful surgical fixation [40], which is sometimes difficult to attain in comminuted fractures of osteoporotic bone. Moreover, there is always a risk of humeral head osteonecrosis despite a successful fixation. As a result, some surgeons advocate primary shoulder arthroplasty as an option to complex proximal humerus fractures.
Primary shoulder hemiarthroplasty performed for proximal humerus fractures showed reasonable early results and prosthesis survivorship [14]. However, while it consistently provides satisfactory long-term pain relief, the restoration of shoulder range of motion and function is less predictable [14,41,42]. Kontakis et al [42] observed 11.15% had complications related to the fixation and healing of tuberosities, with patient’s age and type of prosthesis used being important influential factors. Kralinger et al [43] showed that less than 50% patients were able to flex the shoulder above 90 degrees. Healing of tuberosities at the anatomical location is critical to post-operative function and range of motion [44,45]. Another important criterion for positive outcome is the rotator cuff status [19], which is often difficult to determine in the setting of acute fracture. Even in asymptomatic shoulders, the prevalence of rotator cuff tears is significant and correlate positively with age [46]. The prevalence of rotator cuff tears in a fractured shoulder is even higher than the contralateral uninjured shoulder [47]. Surgeons should always be prepared to convert to other forms of shoulder arthroplasty in cases of intra-operative finding of rotator cuff tears at the involved shoulder.
Classically, rTSA is the preferred surgical treatment of cuff tear arthropathy, which medializes center of rotation, lengthens the deltoid muscle and increases the deltoid lever arm [48]. However, many surgeons borrowed its advantage of being independent to rotator cuff status [49]. Recent literature showed the increased utilization of rTSA as the primary treatment of complex proximal humerus fractures [21,22,50]. The replacement of the glenoid bone may induce additional risks such as instability, glenoid component loosening and scapular notching [51,52]. However, with improved prosthesis design such as less medialized and more inferior glenospheres [53], as well as improved surgical technique such as reattachment of the tuberosities [54], we can hope that the functional outcomes of rTSA will continue to improve while reducing the rate of complications.
The objective of this study is to compare two common treatment modalities – rTSA and IF, in the treatment of geriatric complex proximal humerus fractures. Overall, the improvement rate of shoulder function and range of motion is slower in rTSA before 6 months but better at 2 years. The 2-year outcome of rTSA is similar to other studies in the literature. Bufquin et al [55] evaluated 43 shoulders with mean follow-up of 22 months after rTSA. The mean Constant and the mean modified Constant scores were 44 and 66% respectively. The mean active anterior elevation was 97 degrees and the mean active external rotation in abduction was 30 degrees. Longo et al [56] reviewed 256 patients with mean follow-up of 27.8 months after rTSA. Overall, the mean Constant score was 56.7 ± 7.6 points, the mean DASH score was 39.9 ± 6 points. More recently, Fitschen-Oestern et al [57] evaluated 23 shoulders with mean follow-up of 28.4 months after rTSA. The mean Constant score was 55 ± 13, while the mean shoulder abduction range was 111 degrees, while the external rotation in abduction was 25.87 degrees. However, none of the above papers showed comparison between rTSA and IF in term of early rehabilitation progress, which is important in managing patient’s expectations in the early post-operative period.
Simovitch et al [59] described the post-operative rate of improvement of rTSA – full improvement was achieved by 24 months, although the majority of improvement was achieved in the first 6 months. However, IF has even quicker recovery in very early post-operative phase, given less surgical trauma, surgical duration and length of hospital stay. The DelPhi (Delta prosthesis-PHILOS plate) trial [60] is probably the largest randomized controlled trial on this topic to date. The strength of the study lies in its randomized design, however it included patients from multiple institutions, which each center will inevitably have variability in inclusion, surgical technique and outcome measurement. Our results showed comparable Constant score in the rTSA group in all time intervals consistently, though our results in the IF group performed considerably better than those in the DelPhi trial.
Patients treated with rTSA have worse functional outcome within 6 months after surgery. Controversies exist whether prolonged immobilization is required as protection. Given no patient in our study developed shoulder instability or dislocation, early active mobilization and strengthening may be advocated to improve short-term functional outcome. Enhanced recovery after surgery (ERAS) pathways should be developed after rTSA to accelerate patient’s return to their premorbid function, with emphasis in adequate pain control, early mobilization and to shorten length of hospital stay. Complications are rare following rTSA, and if even they develop, there is usually minimal impact on patient’s function.
Patients treated with IF have worse functional outcome than rTSA from 6 months onwards. Possible ways to improve include maintenance of training until 2 years post-operatively, as well as to employ individualized training – identify the patient’s difficulties in handling specific tasks in daily living or occupation, and train accordingly. Complications are also not uncommon following IF, namely screw penetration, loss of reduction and avascular necrosis. Frequent clinical and radiological assessment and early recognition of these adverse events are essential to optimize patient’s long term function.
This study has its own limitations. Firstly, it is a retrospective study, and not immune to selection bias. The IF group predominantly consists of 3-part fractures while the rTSA group predominantly consists of 4-part fractures. Theoretically, rTSA following a 3-part or 4-part fractures should not make much of a difference. Secondly, no randomization was performed. However, propensity score was matched between the two groups to limit confounding factors. Thirdly, it has a small sample size (25 rTSA vs 25 IF), though with more rTSA being performed at our institute in the future, we will be able to obtain more data.
This is the first study that provides an in-depth analysis on the early rehabilitation progress between the two different treatment groups. The strength of this study includes a direct comparison between the two groups, with propensity scored matching to control for confounders. Its single-centred design can minimize variability in inclusion, surgical technique, rehabilitation protocol and outcome measurement.