2.1.1 Clinical outcomes

As SOT practices have improved, the life span of SOT patients has increased, and with it the demand for total hip arthroplasty (THA). As patients live longer, osteoarthritic indications for THA emerge. Meanwhile, the use of steroids and immunosuppressants following SOT surgeries increases avascular necrosis (AVN) indications. Studies have shown that as many as 5–20% of SOT patients will go on to develop AVN.^12,13

Studies have highlighted significant improvements in pain relief, functional restoration, and overall quality of life for SOT patients who undergo THA.^14,15 Notably, Ledford et al. reported that 82%–100% of SOT patients achieved good or excellent outcomes in patient-reported outcomes (PROs), with an average increase in Harris hip score from 37.5 to 50.7 points.¹⁶ This improvement surpasses the clinically meaningful threshold of 16–18 points.¹⁷ Despite these positive results, certain challenges persist in clinical outcomes. For AVN patients undergoing TSA, those with prior SOT required an average of $2382 more in healthcare spending and an average of 0.44 more days in the hospital compared to patients without SOT.¹⁸ Other studies corroborate these findings, indicating prolonged LOS and elevated post-operative care requirements.^7,16,19 In the case of revision THA, SOT patients experienced extended hospital stays (mean duration >5 days) and a considerable rate of discharge to extended care facilities (63% of cases).¹⁵ Furthermore, Upfill-Brown et al. found that SOT patients undergoing revision THA for aseptic indications had higher 90-day all-cause readmission rates, but not readmissions related to revision THA-related complications.²⁰

Discrepancies exist in the literature regarding the relationship between SOT and mortality. Some studies observe parity in mortality between SOT and non-SOT patients,^20–22 while others point to elevated mortality rates among SOT patients, with odds ratios as high as 4.13 (p = 0.038).²³ In direct comparisons, SOT patients showed increased mortality (odds ratio 7.42, p < 0.001) following primary THA, however, the cause of mortality in patients was related to the transplanted organ in most cases.¹⁹ Similar trends were seen in one-year mortality rates after revision THA in renal transplant patients.²⁴ The literature examining mortality between different solid organs had heterogeneous results. While Wu et al. observed elevated mortality rates in lung transplant patients, Chalmers et al. detected no significant differences in mortality among various types of solid organ transplant recipients.^25,26 These statistics must be considered within the broader context of SOT survivorship, where 5-year survival rates for renal, liver, and heart transplant recipients stand at 81%, 81.2%, and 80% respectively.^27–29

2.1.2 Complications

The inclusion of THA in solid organ transplant recipient's care offers a nuanced but beneficial clinical outcome profile. However, the current literature on the complication and revision rates in these patients offers a mixed picture, with certain studies noting increased complication rates in SOT patients with others finding no difference from control populations.

A 367,894 patient database study by Varatharaj et al. found a substantially higher risk of postoperative complications for organ transplant patients, encompassing anemia, acute renal failure (ARF), transfusion necessity, prosthetic dislocations, wound complications, and deep surgical-site infections in SOT patients after THA.²³ Similarly, Navale et al. documented heightened complications in the SOT group, primarily concerning the need for allogeneic blood transfusions. However, even after excluding transfusion-related complications, SOT patients exhibited significantly elevated complications compared to their non-SOT counterparts.²² Parallel findings are evident in other studies, which compared SOT to non-SOT in THA patients and found increased complication rates of ARF, blood transfusions, increased intraoperative blood loss, hyperkalemia, deep vein thrombosis, sepsis, wound complication, and prosthetic joint infection (PJI).^{7,14,16,26,30–34} PJI and septicemia also emerged as troublesome complications in the SOT revision THA population.^15,24 For instance, in one study, PJI infections were the indication for 23% of revision THA in SOT patients, and responsible for 10% of re-revision THAs.¹⁵

In contrast to the above, multiple studies have found no increased risk of complications for SOT patients following THA in their cohorts. Quinlan et al. found no elevated risk of complications in patients with SOT undergoing THA for AVN.¹⁸ Brown et al. reported no difference in infection rates for SOT patients undergoing THA.¹⁹ Finally, studies specifically looking at liver transplant patients undergoing THA found no significant differences in complications or dislocations compared to control groups.^8,21

2.1.3 Implant survivorship

SOT patients undergoing THA have shown excellent implant survival. Chalmers et al. reported implant survival rates of 94% at two years and 92% at five years following THA, with no discernible influence from SOT type or surgical indication.²⁶ Wu et al. reported on TJA outcomes (TKA and THA) in SOT patients and found implant survivorship of 96% a one year, and 92% at four years.²⁵ Notably, Goffin et al. showcased impressive implant survival of 99% at 10 years and 64% at 20 years of cemented hardware in renal SOT THA patients, results equivalent to those obtained in the general population.³⁵ This trend extends to revision THA in SOT patients, with Ledford et al. demonstrating implant survival rates of 82% ± 7% at 2, 5, and 10 years, outcomes that mirror implant survival in control revision THA patients.¹⁵ An overview of the reviewed literature can be found in Table 1.

2.2.1 Clinical outcomes

Solid organ transplants have prolonged the lifespan of patients, thus increasing the incidence of knee arthritis and subsequent total knee arthroplasty (TKA). Clinical outcomes of this patient cohort have been studied to determine whether patients have improved pain, function, and quality of life after a TKA.

Boquet et al. performed an early retrospective study on 16 TKAs after renal transplantation and found that the mean Knee Society Score (KSS) was 97.1 and the mean functional score was 87.7.³⁶ Ledford et al. performed a retrospective review, identifying 21 TKAs with follow-up averaging 41.2 months.¹⁶ They found that objective KSS increased from 53.6 preoperatively to 90.7 postoperatively, with functional KSS increasing from 60.5 to 84.3 in all but the liver transplant cohort. An additional study from Ledford et al. analyzing 5 TKAs after lung transplant again found that 3 patients reported their outcomes as good and two reported it as excellent after a mean follow-up of 42.8 months.³⁷

These studies, although limited in sample size, suggest that patients who have had solid organ transplants are overall satisfied with their TKAs and report better function afterward. It is important to balance these positive outcomes with the risk of complications.

2.2.2 Complications

Patients with a history of SOT may have an increased risk of perioperative complications after TKA due to immunosuppressant use or other metabolic derangements. A previously described retrospective study of 21 TKAs by Ledford et al. found that there was a high rate of complications (33%), hospital length of stay (3.7 days), and reoperations (9.1%) in the TKA cohort.¹⁶ Additionally, 3 TKAs required two-stage revisions for infection.

Klika et al. analyzed perioperative complications in TKA patients from 1998 to 2011, comparing 6104 with SOT out of 5,870,421 total TKA patients.¹¹ They found that these patients had a 0.44 day increased length of stay, had a 43% higher likelihood of experiencing any complication (p = 0.0002), had more renal complications (p = 0.0099) and required a transfusion (p < 0.0001).

A retrospective review by Klement et al. compared 3339 patients who underwent TKA after 1 or more solid organ transplants to a control group of 1,685,295 patients.³⁸ Analysis of postoperative complications revealed an increase in postoperative complications at 90 days versus other time points. Additionally, there were increases overall in periprosthetic infection (p < 0.001) and fracture (p < 0.001) as well as TKA revision (p = 0.001). They found that patients who had received heart and lung transplants had the fewest complications. These findings are consistent with that of Klatt et al.³⁹ They examined 11 TKAs after renal transplant and 12 after non-renal solid organ transplant and found that infection rates were higher in patients with kidney transplants compared to other solid organs (liver, heart, lung). These studies suggest that renal transplantation is associated with increased postoperative complications.

Ledford et al. performed a retrospective study on 96 TKAs from 76 patients after solid organ transplant with a mean follow-up of 4 years.⁴⁰ They found that the 1 year, 2 years, and 5 years mortality rates from TKA were 2.6%, 7.9%, and 13.2%, respectively. This study also found perioperative complications at a rate of 12.5%, which included periprosthetic fractures (5.2%) and deep periprosthetic infections (3.2%).

Although much of the literature suggests an increased risk of perioperative complications in this patient cohort, a systematic review from 1980 to 2008 demonstrated relatively few.⁴¹ The review compiled 8 studies, for a total of 51 TKAs with a mean follow-up of 60 months. One study documented a patient's death from multi-organ failure due to infection, while the other studies reported no or minor complications. Taken collectively, these studies suggest that TKAs may be offered to patients with a history of SOT but should be monitored with a high index of suspicion for early infection.

2.2.3 Implant survival

Implant survival in patients with SOT who received TKAs has not been extensively studied.²⁵ Wu et al. analyzed 119 THAs and 63 TKAs and found that overall implant survivorship was 95.6% at one year and 92.1% at four years. In the TKA cohort, 4 patients required revisions, with 3 due to prosthetic joint infection and 1 due to painful TKA. A previously mentioned study by Ledford et al. isolated patients with TKAs and demonstrated that implant survivorship without any revision or removal was 98% at 2 years and 93% at 5 years.⁴⁰ Thus, there is limited literature to date on implant survivorship, and this is an area of future study. An overview of the reviewed literature can be found in Table 2.

2.3.1 Clinical outcomes

Overall clinical outcomes from total shoulder arthroplasty (TSA) between SOT and non-SOT recipients remain similar, with generally positive medical outcomes,^9,41–43 and a high degree of patient satisfaction between both groups.^9,42 Negligible statistical variation was discovered between both groups in length of hospital stay (p = 0.85), intraoperative complications (p = 0.79), and revision (p = 1.00).^2,9,43 The lack of variation in length of hospital stay suggests that SOT recipients do as well immediately postoperatively as their non-SOT counterparts, and can be discharged at relatively the same rates.

The literature remains divided in postoperative range of motion (ROM) between SOT and non-SOT patients. A recent meta-analysis reported no significant difference in postoperative forward elevation (p = 0.08), external rotation (p = 0.84) and ASES scores (p = 0.11) between the groups postoperatively. Even when SOT patients had lower ROM, Rizk et al. still found these patients benefit from arthroplasty and the emphasis should be on preoperative counseling.⁴³

2.3.2 Complications

As noted prior, the literature reported a lack of statistically significant evidence of difference in complication rates between SOT and non-SOT patients.^2,9,43 Where the literature varies is in the type of medical complications seen postoperatively. Malcolm et al. reported higher rates of genitourinary infection (p < 0.001), while Rizk et al. reported a higher rate of blood transfusion compared to non-SOT (p = 0.02). These transfusions were performed for a variety of medical conditions, but the authors note that this increase in transfusion is linked more likely to preoperative anemia as opposed to history of SOT.⁴³ The literature does note that SOT patients usually report much sicker at baseline than non-SOT patients (p < 0.001) which may potentially impact the type and frequency of medical complications seen post-operatively.²

Previous studies have also reported a higher instance of death in SOT patients versus control.^9,43 However, the literature notes that it is difficult to attribute the deaths to any complication of shoulder arthroplasty since death occurred an average 1578 days postoperatively in the SOT group versus 1985 days for control.⁴³ As a result, many of deaths are viewed not as a complication of shoulder arthroplasty, but as a further progression of pre-existing conditions that SOT patients typically present with upon evaluation for shoulder arthroplasty.^2,43

2.3.3 Implant survival

Currently, there exists little literature discussing shoulder implant survivorship among SOT recipients. In spite of this, the literature currently available reports that there is no significant variation in revision history between SOT patients and non-SOT patients long term, suggesting a similar implant survivorship.^9,42 However, literature does note that such conclusions are difficult to assess due to a lack of studies that perform long term follow-up (5–10 years) on SOT patients to truly affirm any variation in revision between groups.⁹ Additionally, SOT patients have demonstrated higher mortality rates in the initial 5–10 year period following TSA, so it may be more challenging to ascertain prosthesis survivorship in this population. An overview of the reviewed literature can be found in Table 3.