In an evaluation of 275 consecutive Navy patients for shoulder complaints, Provencher et al. [6] found that those patients who underwent surgery to correct their pathology (instability, rotator cuff, or labral tear) had outcome scores that were lower than those of patients who were treated nonoperatively. This suggests that patients with shoulder injuries sustained on active duty that require surgical treatment may continue to have persistent pain and decreased function after repair. Obviously, those patients who were treated nonoperatively likely had less serious shoulder conditions than those who underwent operative treatment, but the finding remains important when counseling patients on their expected prognosis. Furthermore, their study found that the outcome scores were similar across the different shoulder conditions (superior labrum anterior and posterior tears, rotator cuff tears, and shoulder instability) evaluated [6]. These findings suggest that it may simply be the fact that the shoulder is injured that determines the outcome as much as it is the type of injury or method of fixation.

A similar study looked at 179 active duty Navy patients who were prospectively evaluated for type 2 superior labrum anterior and posterior (SLAP) tears and followed for close to 4 years. This study showed an improvement in the mean Single Assessment Numeric Evaluation (SANE) score from 50 to 85 and the mean American Shoulder and Elbow Surgeons Standardized Shoulder Assessment (ASES) score from 65 to 88 after repair. Considering that any score above 90 is considered a “normal” shoulder, these results indicate that type 2 SLAP tears can be reliably fixed, and most patients can return to their baseline activities [7].

When specifically looking at shoulder instability, the age at which the patient first dislocates his shoulder seems to matter more than anything else [8]. Older patients who undergo surgical treatment for their instability with a Bankart procedure are less likely to have recurrent instability than a younger person. In fact, one study found that there is a 7 % decrease in dislocation rate for each year older a patient is when they undergo the Bankart repair [8]. In an analysis of 3854 military personnel who underwent a Bankart repair, 5 % underwent revision surgery for instability, and 8.8 % were medically discharged with complaints of shoulder instability at 2–7 years of follow-up [9]. When extrapolating literature looking at the return to sports from the civilian literature, around 90 % of athletes can expect to return to their previous level of activity around 6 months following surgery with an average increase of 20 points on their ASES [8, 10, 11]. However, it should be noted that a history of multiple dislocations and trying to return to the previous level of activity without taking enough time off for rehabilitation or surgery decreases the likelihood of a patient making a full recovery [11, 12]. In terms of chronic disability after surgical repair, there appears to be a relatively low level of osteoarthritis (OA) that develops after either arthroscopic or open Bankart repairs; however, this may be dependent on the degree of glenoid and/or humeral head bone loss [13]. In more severe cases of instability where bone loss is present and a Laterjet procedure is indicated, the outcomes also appear to be promising. In an analysis of 68 Latarjet procedures in young adults, the mean Rowe score increased almost 38 points during the 20-year study period [14]. Patients who are undergoing a Laterjet procedure for instability, however, are at a higher risk of developing OA compared to those patients who are able to be treated with a Bankart procedure alone [15].

There are not any military-specific studies that examine outcomes after rotator cuff injuries. However, Provencher et al. showed that rotator cuff repairs faired no better or worse than SLAP tears or cases of shoulder instability in terms of functional outcome scores after surgery [6].

A review of 78 workers’ compensation patients who underwent arthroscopic rotator cuff repair of full-thickness rotator cuff repairs showed that almost 90 % of the patients were able to return to their preoperative level of work at an average of 7.6 months [16]. These findings suggest that active duty personnel who have not returned to full duty at a year may be unlikely to do so with further recovery. Recovery may also depend on the physical demands of each patient’s job as patients who do lighter-duty work returned to work at a higher rate than those who did heavy work [16]. Vocation aside, the vast majority of patients who undergo a repair for a rotator cuff injury have a good outcome at 1 and 2 years after their injury [17, 18]. There has been little to no work assessing return to duty after elbow or wrist injury .

Upper extremity amputations have dramatic affects on patient disability [19, 20]. Despite advances in prosthetic and rehabilitation options [21], a recent study comparing upper extremity amputees from the Vietnam war with upper extremity amputees from the Operation Iraqi Freedom/Operation Enduring Freedom (OIF/OEF) conflicts suggests that there is little change in patient satisfaction between groups [22]. In addition, research suggests that, as a whole, upper extremity amputees have significantly higher disability ratings and are significantly less likely to be found fit for duty compared to lower extremity amputees [23].

One reason that prosthetic advances may not be having a greater impact on patient satisfaction is that many upper extremity amputees tend to avoid using their prostheses. Recent data suggest that 30–50 % of all upper extremity amputees, regardless of prostheses type, report minimal daily usage of their prosthetic limb [22]. Additionally, only 50 % of OIF/OEF upper extremity amputees who have a myoelectric device use it daily, whereas 68 % of OIF/OEF upper extremity amputees use their mechanical device daily [22]. Less frequent prosthetic usage may be part of the reason why patients who have a more distal upper extremity amputation report increased life satisfaction than patients with proximal amputations [22] as they may be less reliant on the prosthesis for function .

For upper extremity amputations taking place at least 90 days after the date of injury, it is important to note that performing a late upper extremity amputation may not completely eliminate some of the associated problems with the salvaged limb. One study of these patients showed that half of the patients who underwent late upper extremity amputation in part because of the heterotopic ossification and neurogenic pain in their limb had recurrence of those issues postoperatively [24].

There is very little research assessing outcomes or associated disabilities with upper extremity limb salvage. There is strong historic dogma that even a minimally functional upper extremity is better than no upper extremity at all [19, 20, 24]. While there may be some truth to this line of thinking [25], complications, such as heterotopic ossification, neuroma formation, and infection, are common in this patient cohort [24, 26].

There has only been one study examining the outcomes and disabilities associated with cartilage preservation and restoration knee surgery within the military. In a review of 38 consecutive osteochondral autografts at a single institution, 42 % were unable to return to duty in any form because of continued disability related to their operative knee. Of the 29 % of patients returned to full duty, only two stated that they were symptom free and could continue unrestricted activity [33]. Although there are many possible confounders that could affect these results, this study shows that cartilage defects within the knee prevent nearly all military personnel from returning to their pre-injury level of function.

These military-specific findings are in stark contrast to published reports for college and professional athletes. Those studies have found that 65–79 % of athletes reached their pre-injury level of sports within a year of surgical treatment of the cartilage lesion, and close to 90 % were able to return in a limited capacity [34, 35]. Age greater than 25 and preoperative symptoms lasting longer than 12 months negatively affected an athlete’s ability to return to sports [34]. It is unclear why these results have not been replicated within the military.

There is no literature that examines the short- or long-term disabilities encountered by active duty personnel who sustain anterior cruciate ligament (ACL) injuries, and the civilian literature looking at such outcomes vary widely [36]. However, it may be possible to extrapolate earlier studies examining an athlete’s ability to return to play to a service member’s ability to return to duty. Although between 60 and 80 % of high school and college athletes return to their previous level of competition following ACL reconstruction [37, 38], only 40 % of athletes thought they returned to their previous level of performance after ACL reconstruction [38]. As many as 85 % of patients who sustain an ACL injury go on to experience eventual posttraumatic osteoarthritis (PTOA) of the injured knee, and one study suggested that the ACL rupture was equivalent to adding 30 years of degenerative wear to the native knee [39]. While these estimates may be high, they indicate that even if service members are able to return to duty after an ACL injury, it is likely that their injured knee will cause them some type of late disability.

Interestingly enough, it appears that the status of the menisci at the time of ACL injury is the main determinant of developing PTOA [39]. Service members injure their menisci at a rate that is almost ten times as high as civilian population [40, 41]. Yet, there are no studies specifically looking at the outcomes or persistent disability these injuries cause service members. While the civilian literature details outcomes that are often good or excellent, it is difficult to translate these results to an active duty population secondary to the unique physical demands of military personnel. Meniscus transplantation is an intriguing treatment option for young, active military personnel who have severe meniscal injuries, but the long-term outcome of this procedure is not established [40].

Lower extremity amputation is the fifth most common unfitting condition for service members who were injured in battle and the injury that has the greatest disability impact when accounting for the percent of disability for each injury and the frequency with which each disability appeared [5]. These facts speak to the short- and long-term debility associated with these injuries for service members.

According to the military-specific Military Extremity Trauma Amputation/Limb Salvage (METALS) study, amputees have improved patient-reported outcome scores compared to limb salvage patients who sustained similar injuries [42]. However, these patients sustained their injury and amputation prior to the development of more focused limb salvage rehabilitation and the Intrepid Dynamic Exoskeletal Orthosis (IDEO). The METALS conclusions suggest that focused rehabilitation may be the largest determinant of outcomes, in the limb-loss cohort, leading to their improved outcome [43].

One study found no difference in SF-36 scores or Prosthesis Evaluation Questionnaire subsections between transtibial amputees undergoing modified-Ertl and modified-Burgess transtibial amputations. However, those amputees who underwent a modified Ertl amputation were significantly more likely to require a revision amputation [44]. For those service members who undergo a hip disarticulation or transpelvic amputation, they are likely to require lifelong assistance and will do better in mental outcome scores than physical outcome scores [45].

When evaluating the ability of amputees to return to duty and be deployed, amputees have been found to have a return-to-duty rate of 12.5 % after type III tibial fracture [46]. This rate is lower than the 20.5 % rate of return to duty for those limb salvage patients sustaining the same injury and the 51 % of those service members undergoing limb salvage for a lower extremity injury who participated in the return-to-run (RTR) pathway using an IDEO [47]. Only 5 % of all combat-related amputees deploy after their amputation. However, members of the Special Forces deploy at a 48 % rate after amputation. This increased rate likely stems from them having a greater psychosocial support and increased incentive compared to the general military population [48].

Lower Extremity Assessment Project (LEAP) data concluded no differences between limb salvage and amputations. The METALS study found worse outcomes with limb salvage and also lower return to vigorous activity and significantly higher depression screening [49, 50]. However, in a prospective study of limb salvage patients who were able to use IDEO and RTR pathway, there was significant improvement in their measured physical abilities, pain, and self-assessment tests at the 4- and 8-week evaluation points. Just as importantly, 41 of the 50 patients who were initially considering amputation at the start of the study for their injured lower extremity favored limb salvage after 8 weeks of training and rehabilitation with IDEO and RTR [49].

Still, between 10 and 15 % of those patients who attempt lower extremity limb salvage go on to seek a late amputation [51, 52]. Additionally, research has shown that those service members who sustain complications related to their salvaged tibia and hindfoot injuries are significantly less likely to return to duty than those who did not [53, 54]. Lastly, PTOA, the most common disabling condition for those service members who are injured in battle [5], is thought to be quite prevalent among the limb salvage population.